diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7368905f5f..46b723bcf6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
   - `icu_calendar`
     - Consistently name calendar-specific `Date`/`DateTime` functions that have a calendar argument (https://github.com/unicode-org/icu4x/pull/5692)
     - Move all calendar types to `cal` module (https://github.com/unicode-org/icu4x/pull/5701)
+    - Shorten integer types returned by `day_of_month()`, `week_of_month()`, and `week_of_year()` to `u8` (https://github.com/unicode-org/icu4x/pull/5702)
   - `icu_collections`
   - `icu_normalizer`
   - `icu_datetime`
diff --git a/components/calendar/src/any_calendar.rs b/components/calendar/src/any_calendar.rs
index 232c9bc76c..c1a15b9848 100644
--- a/components/calendar/src/any_calendar.rs
+++ b/components/calendar/src/any_calendar.rs
@@ -1864,7 +1864,6 @@ mod tests {
 
     use super::*;
     use crate::Ref;
-    use core::convert::TryInto;
 
     fn single_test_roundtrip(
         calendar: Ref<AnyCalendar>,
@@ -1889,7 +1888,7 @@ mod tests {
         let roundtrip_era = roundtrip_year.formatting_era().unwrap_or(era);
         let roundtrip_year = roundtrip_year.era_year_or_extended();
         let roundtrip_month = date.month().standard_code;
-        let roundtrip_day = date.day_of_month().0.try_into().expect("Must fit in u8");
+        let roundtrip_day = date.day_of_month().0;
 
         assert_eq!(
             (era, year, month, day),
diff --git a/components/calendar/src/buddhist.rs b/components/calendar/src/buddhist.rs
index f889d45ce5..be399d8f05 100644
--- a/components/calendar/src/buddhist.rs
+++ b/components/calendar/src/buddhist.rs
@@ -342,7 +342,7 @@ mod test {
         );
         assert_eq!(
             buddhist1.day_of_month().0,
-            buddhist_day as u32,
+            buddhist_day,
             "Iso -> Buddhist day check failed for case: {case:?}"
         );
 
@@ -361,7 +361,7 @@ mod test {
         );
         assert_eq!(
             iso2.day_of_month().0,
-            iso_day as u32,
+            iso_day,
             "Buddhist -> Iso day check failed for case: {case:?}"
         );
     }
diff --git a/components/calendar/src/calendar_arithmetic.rs b/components/calendar/src/calendar_arithmetic.rs
index 15edd8ca93..2bd38cb3db 100644
--- a/components/calendar/src/calendar_arithmetic.rs
+++ b/components/calendar/src/calendar_arithmetic.rs
@@ -300,7 +300,7 @@ impl<C: CalendarArithmetic> ArithmeticDate<C> {
 
     #[inline]
     pub fn day_of_month(&self) -> types::DayOfMonth {
-        types::DayOfMonth(self.day.into())
+        types::DayOfMonth(self.day)
     }
 
     /// The [`types::MonthInfo`] for the current month (with month code) for a solar calendar
diff --git a/components/calendar/src/chinese.rs b/components/calendar/src/chinese.rs
index 4ad5659957..bb9622aec2 100644
--- a/components/calendar/src/chinese.rs
+++ b/components/calendar/src/chinese.rs
@@ -285,7 +285,7 @@ impl Calendar for Chinese {
 
     /// The calendar-specific day-of-month represented by `date`
     fn day_of_month(&self, date: &Self::DateInner) -> types::DayOfMonth {
-        types::DayOfMonth(date.0 .0.day as u32)
+        types::DayOfMonth(date.0 .0.day)
     }
 
     /// Information of the day of the year
@@ -666,7 +666,7 @@ mod test {
             iso_day: u8,
             expected_year: i32,
             expected_month: u8,
-            expected_day: u32,
+            expected_day: u8,
         }
 
         let cases = [
@@ -1006,7 +1006,7 @@ mod test {
             expected_rel_iso: i32,
             expected_cyclic: u8,
             expected_month: u8,
-            expected_day: u32,
+            expected_day: u8,
         }
 
         let cases = [
diff --git a/components/calendar/src/dangi.rs b/components/calendar/src/dangi.rs
index fe7dda0a97..d2c0b708c6 100644
--- a/components/calendar/src/dangi.rs
+++ b/components/calendar/src/dangi.rs
@@ -266,7 +266,7 @@ impl Calendar for Dangi {
     }
 
     fn day_of_month(&self, date: &Self::DateInner) -> crate::types::DayOfMonth {
-        types::DayOfMonth(date.0 .0.day as u32)
+        types::DayOfMonth(date.0 .0.day)
     }
 
     fn day_of_year_info(&self, date: &Self::DateInner) -> crate::types::DayOfYearInfo {
@@ -492,7 +492,7 @@ mod test {
             expected_rel_iso: i32,
             expected_cyclic: u8,
             expected_month: u8,
-            expected_day: u32,
+            expected_day: u8,
         }
 
         let cases = [
diff --git a/components/calendar/src/gregorian.rs b/components/calendar/src/gregorian.rs
index b948066683..e0e3ac26cb 100644
--- a/components/calendar/src/gregorian.rs
+++ b/components/calendar/src/gregorian.rs
@@ -374,7 +374,7 @@ mod test {
         expected_year: i32,
         expected_era: Era,
         expected_month: u8,
-        expected_day: u32,
+        expected_day: u8,
     }
 
     fn check_test_case(case: TestCase) {
diff --git a/components/calendar/src/indian.rs b/components/calendar/src/indian.rs
index db220014a9..72681c2f03 100644
--- a/components/calendar/src/indian.rs
+++ b/components/calendar/src/indian.rs
@@ -329,7 +329,7 @@ mod tests {
             "{y}-{m}-{d}: ISO month did not match"
         );
         assert_eq!(
-            iso.day_of_month().0 as u8,
+            iso.day_of_month().0,
             iso_d,
             "{y}-{m}-{d}: ISO day did not match"
         );
@@ -376,7 +376,7 @@ mod tests {
         iso_day: u8,
         expected_year: i32,
         expected_month: u8,
-        expected_day: u32,
+        expected_day: u8,
     }
 
     fn check_case(case: TestCase) {
diff --git a/components/calendar/src/julian.rs b/components/calendar/src/julian.rs
index 15500a24e6..036f9f798a 100644
--- a/components/calendar/src/julian.rs
+++ b/components/calendar/src/julian.rs
@@ -420,7 +420,7 @@ mod test {
             expected_year: i32,
             expected_era: Era,
             expected_month: u8,
-            expected_day: u32,
+            expected_day: u8,
         }
 
         let cases = [
diff --git a/components/calendar/src/persian.rs b/components/calendar/src/persian.rs
index 7a1b615ea7..bd785d229f 100644
--- a/components/calendar/src/persian.rs
+++ b/components/calendar/src/persian.rs
@@ -534,7 +534,7 @@ mod tests {
 
     // From https://calendar.ut.ac.ir/Fa/News/Data/Doc/KabiseShamsi1206-1498-new.pdf
     // Plain text version at https://github.com/roozbehp/persiancalendar/blob/main/kabise.txt
-    static CALENDAR_UT_AC_IR_TEST_DATA: [(i32, bool, i32, u8, u32); 293] = [
+    static CALENDAR_UT_AC_IR_TEST_DATA: [(i32, bool, i32, u8, u8); 293] = [
         (1206, false, 1827, 3, 22),
         (1207, false, 1828, 3, 21),
         (1208, false, 1829, 3, 21),
diff --git a/components/calendar/src/roc.rs b/components/calendar/src/roc.rs
index dcb3ff3e13..6fbfd9eaa0 100644
--- a/components/calendar/src/roc.rs
+++ b/components/calendar/src/roc.rs
@@ -300,7 +300,7 @@ mod test {
         expected_year: i32,
         expected_era: Era,
         expected_month: u8,
-        expected_day: u32,
+        expected_day: u8,
     }
 
     fn check_test_case(case: TestCase) {
diff --git a/components/calendar/src/types.rs b/components/calendar/src/types.rs
index ec87545f5a..7e18d35c93 100644
--- a/components/calendar/src/types.rs
+++ b/components/calendar/src/types.rs
@@ -331,22 +331,22 @@ pub struct DayOfYearInfo {
 /// A day number in a month. Usually 1-based.
 #[allow(clippy::exhaustive_structs)] // this is a newtype
 #[derive(Clone, Copy, Debug, PartialEq)]
-pub struct DayOfMonth(pub u32);
+pub struct DayOfMonth(pub u8);
 
 /// A week number in a month. Usually 1-based.
 #[derive(Clone, Copy, Debug, PartialEq)]
 #[allow(clippy::exhaustive_structs)] // this is a newtype
-pub struct WeekOfMonth(pub u32);
+pub struct WeekOfMonth(pub u8);
 
 /// A week number in a year. Usually 1-based.
 #[derive(Clone, Copy, Debug, PartialEq)]
 #[allow(clippy::exhaustive_structs)] // this is a newtype
-pub struct WeekOfYear(pub u32);
+pub struct WeekOfYear(pub u8);
 
 /// A day of week in month. 1-based.
 #[derive(Clone, Copy, Debug, PartialEq)]
 #[allow(clippy::exhaustive_structs)] // this is a newtype
-pub struct DayOfWeekInMonth(pub u32);
+pub struct DayOfWeekInMonth(pub u8);
 
 impl From<DayOfMonth> for DayOfWeekInMonth {
     fn from(day_of_month: DayOfMonth) -> Self {
diff --git a/components/calendar/src/week_of.rs b/components/calendar/src/week_of.rs
index 1128d3a632..1536e906a9 100644
--- a/components/calendar/src/week_of.rs
+++ b/components/calendar/src/week_of.rs
@@ -84,7 +84,11 @@ impl WeekCalculator {
     ///
     /// [1]: https://www.unicode.org/reports/tr35/tr35-55/tr35-dates.html#Date_Patterns_Week_Of_Year
     pub fn week_of_month(&self, day_of_month: DayOfMonth, iso_weekday: IsoWeekday) -> WeekOfMonth {
-        WeekOfMonth(simple_week_of(self.first_weekday, day_of_month.0 as u16, iso_weekday) as u32)
+        WeekOfMonth(simple_week_of(
+            self.first_weekday,
+            day_of_month.0 as u16,
+            iso_weekday,
+        ))
     }
 
     /// Returns the week of year according to the weekday and [`DayOfYearInfo`].
@@ -169,7 +173,7 @@ enum RelativeWeek {
     /// A week that is assigned to the last week of the previous year/month. e.g. 2021-01-01 is week 54 of 2020 per the ISO calendar.
     LastWeekOfPreviousUnit,
     /// A week that's assigned to the current year/month. The offset is 1-based. e.g. 2021-01-11 is week 2 of 2021 per the ISO calendar so would be WeekOfCurrentUnit(2).
-    WeekOfCurrentUnit(u16),
+    WeekOfCurrentUnit(u8),
     /// A week that is assigned to the first week of the next year/month. e.g. 2019-12-31 is week 1 of 2020 per the ISO calendar.
     FirstWeekOfNextUnit,
 }
@@ -213,7 +217,7 @@ impl UnitInfo {
     }
 
     /// Returns the number of weeks in this unit according to `calendar`.
-    fn num_weeks(&self, calendar: &WeekCalculator) -> u16 {
+    fn num_weeks(&self, calendar: &WeekCalculator) -> u8 {
         let first_week_offset = self.first_week_offset(calendar);
         let num_days_including_first_week =
             (self.duration_days as i32) - (first_week_offset as i32);
@@ -221,7 +225,7 @@ impl UnitInfo {
             num_days_including_first_week >= 0,
             "Unit is shorter than a week."
         );
-        ((num_days_including_first_week + 7 - (calendar.min_week_days as i32)) / 7) as u16
+        ((num_days_including_first_week + 7 - (calendar.min_week_days as i32)) / 7) as u8
     }
 
     /// Returns the week number for the given day in this unit.
@@ -232,7 +236,7 @@ impl UnitInfo {
             return RelativeWeek::LastWeekOfPreviousUnit;
         }
 
-        let week_number = (1 + days_since_first_week / 7) as u16;
+        let week_number = (1 + days_since_first_week / 7) as u8;
         if week_number > self.num_weeks(calendar) {
             return RelativeWeek::FirstWeekOfNextUnit;
         }
@@ -257,7 +261,7 @@ pub enum RelativeUnit {
 #[allow(clippy::exhaustive_structs)] // this type is stable
 pub struct WeekOf {
     /// Week of month/year. 1 based.
-    pub week: u16,
+    pub week: u8,
     /// The month/year that this week is in, relative to the month/year of the input date.
     pub unit: RelativeUnit,
 }
@@ -316,7 +320,7 @@ pub fn week_of(
 ///  - first_weekday: The first day of a week.
 ///  - day: 1-based day of the month or year.
 ///  - week_day: The weekday of `day`.
-pub fn simple_week_of(first_weekday: IsoWeekday, day: u16, week_day: IsoWeekday) -> u16 {
+pub fn simple_week_of(first_weekday: IsoWeekday, day: u16, week_day: IsoWeekday) -> u8 {
     let calendar = WeekCalculator {
         first_weekday,
         min_week_days: 1,
diff --git a/ffi/capi/bindings/c/Date.h b/ffi/capi/bindings/c/Date.h
index 69b461fcf9..38ba240d9b 100644
--- a/ffi/capi/bindings/c/Date.h
+++ b/ffi/capi/bindings/c/Date.h
@@ -37,11 +37,11 @@ IsoDate* icu4x_Date_to_iso_mv1(const Date* self);
 
 uint16_t icu4x_Date_day_of_year_mv1(const Date* self);
 
-uint32_t icu4x_Date_day_of_month_mv1(const Date* self);
+uint8_t icu4x_Date_day_of_month_mv1(const Date* self);
 
 IsoWeekday icu4x_Date_day_of_week_mv1(const Date* self);
 
-uint32_t icu4x_Date_week_of_month_mv1(const Date* self, IsoWeekday first_weekday);
+uint8_t icu4x_Date_week_of_month_mv1(const Date* self, IsoWeekday first_weekday);
 
 WeekOf icu4x_Date_week_of_year_mv1(const Date* self, const WeekCalculator* calculator);
 
diff --git a/ffi/capi/bindings/c/DateTime.h b/ffi/capi/bindings/c/DateTime.h
index 6e269bf85c..5067ce553b 100644
--- a/ffi/capi/bindings/c/DateTime.h
+++ b/ffi/capi/bindings/c/DateTime.h
@@ -53,11 +53,11 @@ uint32_t icu4x_DateTime_nanosecond_mv1(const DateTime* self);
 
 uint16_t icu4x_DateTime_day_of_year_mv1(const DateTime* self);
 
-uint32_t icu4x_DateTime_day_of_month_mv1(const DateTime* self);
+uint8_t icu4x_DateTime_day_of_month_mv1(const DateTime* self);
 
 IsoWeekday icu4x_DateTime_day_of_week_mv1(const DateTime* self);
 
-uint32_t icu4x_DateTime_week_of_month_mv1(const DateTime* self, IsoWeekday first_weekday);
+uint8_t icu4x_DateTime_week_of_month_mv1(const DateTime* self, IsoWeekday first_weekday);
 
 WeekOf icu4x_DateTime_week_of_year_mv1(const DateTime* self, const WeekCalculator* calculator);
 
diff --git a/ffi/capi/bindings/c/IsoDate.h b/ffi/capi/bindings/c/IsoDate.h
index 9c155e6407..ae7aefcdd5 100644
--- a/ffi/capi/bindings/c/IsoDate.h
+++ b/ffi/capi/bindings/c/IsoDate.h
@@ -36,11 +36,11 @@ Date* icu4x_IsoDate_to_any_mv1(const IsoDate* self);
 
 uint16_t icu4x_IsoDate_day_of_year_mv1(const IsoDate* self);
 
-uint32_t icu4x_IsoDate_day_of_month_mv1(const IsoDate* self);
+uint8_t icu4x_IsoDate_day_of_month_mv1(const IsoDate* self);
 
 IsoWeekday icu4x_IsoDate_day_of_week_mv1(const IsoDate* self);
 
-uint32_t icu4x_IsoDate_week_of_month_mv1(const IsoDate* self, IsoWeekday first_weekday);
+uint8_t icu4x_IsoDate_week_of_month_mv1(const IsoDate* self, IsoWeekday first_weekday);
 
 WeekOf icu4x_IsoDate_week_of_year_mv1(const IsoDate* self, const WeekCalculator* calculator);
 
diff --git a/ffi/capi/bindings/c/IsoDateTime.h b/ffi/capi/bindings/c/IsoDateTime.h
index eea402c69c..c47bbe08b2 100644
--- a/ffi/capi/bindings/c/IsoDateTime.h
+++ b/ffi/capi/bindings/c/IsoDateTime.h
@@ -56,11 +56,11 @@ uint32_t icu4x_IsoDateTime_nanosecond_mv1(const IsoDateTime* self);
 
 uint16_t icu4x_IsoDateTime_day_of_year_mv1(const IsoDateTime* self);
 
-uint32_t icu4x_IsoDateTime_day_of_month_mv1(const IsoDateTime* self);
+uint8_t icu4x_IsoDateTime_day_of_month_mv1(const IsoDateTime* self);
 
 IsoWeekday icu4x_IsoDateTime_day_of_week_mv1(const IsoDateTime* self);
 
-uint32_t icu4x_IsoDateTime_week_of_month_mv1(const IsoDateTime* self, IsoWeekday first_weekday);
+uint8_t icu4x_IsoDateTime_week_of_month_mv1(const IsoDateTime* self, IsoWeekday first_weekday);
 
 WeekOf icu4x_IsoDateTime_week_of_year_mv1(const IsoDateTime* self, const WeekCalculator* calculator);
 
diff --git a/ffi/capi/bindings/c/WeekOf.d.h b/ffi/capi/bindings/c/WeekOf.d.h
index 5217a03fd3..aa4af9555a 100644
--- a/ffi/capi/bindings/c/WeekOf.d.h
+++ b/ffi/capi/bindings/c/WeekOf.d.h
@@ -13,7 +13,7 @@
 
 
 typedef struct WeekOf {
-  uint16_t week;
+  uint8_t week;
   WeekRelativeUnit unit;
 } WeekOf;
 
diff --git a/ffi/capi/bindings/cpp/icu4x/Date.d.hpp b/ffi/capi/bindings/cpp/icu4x/Date.d.hpp
index 0a22c47660..534170ca60 100644
--- a/ffi/capi/bindings/cpp/icu4x/Date.d.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/Date.d.hpp
@@ -47,11 +47,11 @@ class Date {
 
   inline uint16_t day_of_year() const;
 
-  inline uint32_t day_of_month() const;
+  inline uint8_t day_of_month() const;
 
   inline icu4x::IsoWeekday day_of_week() const;
 
-  inline uint32_t week_of_month(icu4x::IsoWeekday first_weekday) const;
+  inline uint8_t week_of_month(icu4x::IsoWeekday first_weekday) const;
 
   inline icu4x::WeekOf week_of_year(const icu4x::WeekCalculator& calculator) const;
 
diff --git a/ffi/capi/bindings/cpp/icu4x/Date.hpp b/ffi/capi/bindings/cpp/icu4x/Date.hpp
index 0e96996e9f..ad8c2a162e 100644
--- a/ffi/capi/bindings/cpp/icu4x/Date.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/Date.hpp
@@ -38,11 +38,11 @@ namespace capi {
     
     uint16_t icu4x_Date_day_of_year_mv1(const icu4x::capi::Date* self);
     
-    uint32_t icu4x_Date_day_of_month_mv1(const icu4x::capi::Date* self);
+    uint8_t icu4x_Date_day_of_month_mv1(const icu4x::capi::Date* self);
     
     icu4x::capi::IsoWeekday icu4x_Date_day_of_week_mv1(const icu4x::capi::Date* self);
     
-    uint32_t icu4x_Date_week_of_month_mv1(const icu4x::capi::Date* self, icu4x::capi::IsoWeekday first_weekday);
+    uint8_t icu4x_Date_week_of_month_mv1(const icu4x::capi::Date* self, icu4x::capi::IsoWeekday first_weekday);
     
     icu4x::capi::WeekOf icu4x_Date_week_of_year_mv1(const icu4x::capi::Date* self, const icu4x::capi::WeekCalculator* calculator);
     
@@ -113,7 +113,7 @@ inline uint16_t icu4x::Date::day_of_year() const {
   return result;
 }
 
-inline uint32_t icu4x::Date::day_of_month() const {
+inline uint8_t icu4x::Date::day_of_month() const {
   auto result = icu4x::capi::icu4x_Date_day_of_month_mv1(this->AsFFI());
   return result;
 }
@@ -123,7 +123,7 @@ inline icu4x::IsoWeekday icu4x::Date::day_of_week() const {
   return icu4x::IsoWeekday::FromFFI(result);
 }
 
-inline uint32_t icu4x::Date::week_of_month(icu4x::IsoWeekday first_weekday) const {
+inline uint8_t icu4x::Date::week_of_month(icu4x::IsoWeekday first_weekday) const {
   auto result = icu4x::capi::icu4x_Date_week_of_month_mv1(this->AsFFI(),
     first_weekday.AsFFI());
   return result;
diff --git a/ffi/capi/bindings/cpp/icu4x/DateTime.d.hpp b/ffi/capi/bindings/cpp/icu4x/DateTime.d.hpp
index 3f064030b0..d13ffd373c 100644
--- a/ffi/capi/bindings/cpp/icu4x/DateTime.d.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/DateTime.d.hpp
@@ -65,11 +65,11 @@ class DateTime {
 
   inline uint16_t day_of_year() const;
 
-  inline uint32_t day_of_month() const;
+  inline uint8_t day_of_month() const;
 
   inline icu4x::IsoWeekday day_of_week() const;
 
-  inline uint32_t week_of_month(icu4x::IsoWeekday first_weekday) const;
+  inline uint8_t week_of_month(icu4x::IsoWeekday first_weekday) const;
 
   inline icu4x::WeekOf week_of_year(const icu4x::WeekCalculator& calculator) const;
 
diff --git a/ffi/capi/bindings/cpp/icu4x/DateTime.hpp b/ffi/capi/bindings/cpp/icu4x/DateTime.hpp
index 1d1a36902b..e23c8a070b 100644
--- a/ffi/capi/bindings/cpp/icu4x/DateTime.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/DateTime.hpp
@@ -54,11 +54,11 @@ namespace capi {
     
     uint16_t icu4x_DateTime_day_of_year_mv1(const icu4x::capi::DateTime* self);
     
-    uint32_t icu4x_DateTime_day_of_month_mv1(const icu4x::capi::DateTime* self);
+    uint8_t icu4x_DateTime_day_of_month_mv1(const icu4x::capi::DateTime* self);
     
     icu4x::capi::IsoWeekday icu4x_DateTime_day_of_week_mv1(const icu4x::capi::DateTime* self);
     
-    uint32_t icu4x_DateTime_week_of_month_mv1(const icu4x::capi::DateTime* self, icu4x::capi::IsoWeekday first_weekday);
+    uint8_t icu4x_DateTime_week_of_month_mv1(const icu4x::capi::DateTime* self, icu4x::capi::IsoWeekday first_weekday);
     
     icu4x::capi::WeekOf icu4x_DateTime_week_of_year_mv1(const icu4x::capi::DateTime* self, const icu4x::capi::WeekCalculator* calculator);
     
@@ -173,7 +173,7 @@ inline uint16_t icu4x::DateTime::day_of_year() const {
   return result;
 }
 
-inline uint32_t icu4x::DateTime::day_of_month() const {
+inline uint8_t icu4x::DateTime::day_of_month() const {
   auto result = icu4x::capi::icu4x_DateTime_day_of_month_mv1(this->AsFFI());
   return result;
 }
@@ -183,7 +183,7 @@ inline icu4x::IsoWeekday icu4x::DateTime::day_of_week() const {
   return icu4x::IsoWeekday::FromFFI(result);
 }
 
-inline uint32_t icu4x::DateTime::week_of_month(icu4x::IsoWeekday first_weekday) const {
+inline uint8_t icu4x::DateTime::week_of_month(icu4x::IsoWeekday first_weekday) const {
   auto result = icu4x::capi::icu4x_DateTime_week_of_month_mv1(this->AsFFI(),
     first_weekday.AsFFI());
   return result;
diff --git a/ffi/capi/bindings/cpp/icu4x/IsoDate.d.hpp b/ffi/capi/bindings/cpp/icu4x/IsoDate.d.hpp
index 5c248a2004..fb48e8a6de 100644
--- a/ffi/capi/bindings/cpp/icu4x/IsoDate.d.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/IsoDate.d.hpp
@@ -47,11 +47,11 @@ class IsoDate {
 
   inline uint16_t day_of_year() const;
 
-  inline uint32_t day_of_month() const;
+  inline uint8_t day_of_month() const;
 
   inline icu4x::IsoWeekday day_of_week() const;
 
-  inline uint32_t week_of_month(icu4x::IsoWeekday first_weekday) const;
+  inline uint8_t week_of_month(icu4x::IsoWeekday first_weekday) const;
 
   inline icu4x::WeekOf week_of_year(const icu4x::WeekCalculator& calculator) const;
 
diff --git a/ffi/capi/bindings/cpp/icu4x/IsoDate.hpp b/ffi/capi/bindings/cpp/icu4x/IsoDate.hpp
index 1203469a74..9810abcf60 100644
--- a/ffi/capi/bindings/cpp/icu4x/IsoDate.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/IsoDate.hpp
@@ -37,11 +37,11 @@ namespace capi {
     
     uint16_t icu4x_IsoDate_day_of_year_mv1(const icu4x::capi::IsoDate* self);
     
-    uint32_t icu4x_IsoDate_day_of_month_mv1(const icu4x::capi::IsoDate* self);
+    uint8_t icu4x_IsoDate_day_of_month_mv1(const icu4x::capi::IsoDate* self);
     
     icu4x::capi::IsoWeekday icu4x_IsoDate_day_of_week_mv1(const icu4x::capi::IsoDate* self);
     
-    uint32_t icu4x_IsoDate_week_of_month_mv1(const icu4x::capi::IsoDate* self, icu4x::capi::IsoWeekday first_weekday);
+    uint8_t icu4x_IsoDate_week_of_month_mv1(const icu4x::capi::IsoDate* self, icu4x::capi::IsoWeekday first_weekday);
     
     icu4x::capi::WeekOf icu4x_IsoDate_week_of_year_mv1(const icu4x::capi::IsoDate* self, const icu4x::capi::WeekCalculator* calculator);
     
@@ -97,7 +97,7 @@ inline uint16_t icu4x::IsoDate::day_of_year() const {
   return result;
 }
 
-inline uint32_t icu4x::IsoDate::day_of_month() const {
+inline uint8_t icu4x::IsoDate::day_of_month() const {
   auto result = icu4x::capi::icu4x_IsoDate_day_of_month_mv1(this->AsFFI());
   return result;
 }
@@ -107,7 +107,7 @@ inline icu4x::IsoWeekday icu4x::IsoDate::day_of_week() const {
   return icu4x::IsoWeekday::FromFFI(result);
 }
 
-inline uint32_t icu4x::IsoDate::week_of_month(icu4x::IsoWeekday first_weekday) const {
+inline uint8_t icu4x::IsoDate::week_of_month(icu4x::IsoWeekday first_weekday) const {
   auto result = icu4x::capi::icu4x_IsoDate_week_of_month_mv1(this->AsFFI(),
     first_weekday.AsFFI());
   return result;
diff --git a/ffi/capi/bindings/cpp/icu4x/IsoDateTime.d.hpp b/ffi/capi/bindings/cpp/icu4x/IsoDateTime.d.hpp
index a913621458..3158790194 100644
--- a/ffi/capi/bindings/cpp/icu4x/IsoDateTime.d.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/IsoDateTime.d.hpp
@@ -69,11 +69,11 @@ class IsoDateTime {
 
   inline uint16_t day_of_year() const;
 
-  inline uint32_t day_of_month() const;
+  inline uint8_t day_of_month() const;
 
   inline icu4x::IsoWeekday day_of_week() const;
 
-  inline uint32_t week_of_month(icu4x::IsoWeekday first_weekday) const;
+  inline uint8_t week_of_month(icu4x::IsoWeekday first_weekday) const;
 
   inline icu4x::WeekOf week_of_year(const icu4x::WeekCalculator& calculator) const;
 
diff --git a/ffi/capi/bindings/cpp/icu4x/IsoDateTime.hpp b/ffi/capi/bindings/cpp/icu4x/IsoDateTime.hpp
index 1dc2f142b5..59da0d02dd 100644
--- a/ffi/capi/bindings/cpp/icu4x/IsoDateTime.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/IsoDateTime.hpp
@@ -57,11 +57,11 @@ namespace capi {
     
     uint16_t icu4x_IsoDateTime_day_of_year_mv1(const icu4x::capi::IsoDateTime* self);
     
-    uint32_t icu4x_IsoDateTime_day_of_month_mv1(const icu4x::capi::IsoDateTime* self);
+    uint8_t icu4x_IsoDateTime_day_of_month_mv1(const icu4x::capi::IsoDateTime* self);
     
     icu4x::capi::IsoWeekday icu4x_IsoDateTime_day_of_week_mv1(const icu4x::capi::IsoDateTime* self);
     
-    uint32_t icu4x_IsoDateTime_week_of_month_mv1(const icu4x::capi::IsoDateTime* self, icu4x::capi::IsoWeekday first_weekday);
+    uint8_t icu4x_IsoDateTime_week_of_month_mv1(const icu4x::capi::IsoDateTime* self, icu4x::capi::IsoWeekday first_weekday);
     
     icu4x::capi::WeekOf icu4x_IsoDateTime_week_of_year_mv1(const icu4x::capi::IsoDateTime* self, const icu4x::capi::WeekCalculator* calculator);
     
@@ -167,7 +167,7 @@ inline uint16_t icu4x::IsoDateTime::day_of_year() const {
   return result;
 }
 
-inline uint32_t icu4x::IsoDateTime::day_of_month() const {
+inline uint8_t icu4x::IsoDateTime::day_of_month() const {
   auto result = icu4x::capi::icu4x_IsoDateTime_day_of_month_mv1(this->AsFFI());
   return result;
 }
@@ -177,7 +177,7 @@ inline icu4x::IsoWeekday icu4x::IsoDateTime::day_of_week() const {
   return icu4x::IsoWeekday::FromFFI(result);
 }
 
-inline uint32_t icu4x::IsoDateTime::week_of_month(icu4x::IsoWeekday first_weekday) const {
+inline uint8_t icu4x::IsoDateTime::week_of_month(icu4x::IsoWeekday first_weekday) const {
   auto result = icu4x::capi::icu4x_IsoDateTime_week_of_month_mv1(this->AsFFI(),
     first_weekday.AsFFI());
   return result;
diff --git a/ffi/capi/bindings/cpp/icu4x/WeekOf.d.hpp b/ffi/capi/bindings/cpp/icu4x/WeekOf.d.hpp
index 190ad638ba..704c259c83 100644
--- a/ffi/capi/bindings/cpp/icu4x/WeekOf.d.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/WeekOf.d.hpp
@@ -18,7 +18,7 @@ class WeekRelativeUnit;
 namespace icu4x {
 namespace capi {
     struct WeekOf {
-      uint16_t week;
+      uint8_t week;
       icu4x::capi::WeekRelativeUnit unit;
     };
     
@@ -29,7 +29,7 @@ namespace capi {
 
 namespace icu4x {
 struct WeekOf {
-  uint16_t week;
+  uint8_t week;
   icu4x::WeekRelativeUnit unit;
 
   inline icu4x::capi::WeekOf AsFFI() const;
diff --git a/ffi/capi/bindings/dart/Date.g.dart b/ffi/capi/bindings/dart/Date.g.dart
index 1bdbd3dc82..1c12fdf5dd 100644
--- a/ffi/capi/bindings/dart/Date.g.dart
+++ b/ffi/capi/bindings/dart/Date.g.dart
@@ -269,7 +269,7 @@ external ffi.Pointer<ffi.Opaque> _icu4x_Date_to_iso_mv1(ffi.Pointer<ffi.Opaque>
 external int _icu4x_Date_day_of_year_mv1(ffi.Pointer<ffi.Opaque> self);
 
 @meta.RecordUse()
-@ffi.Native<ffi.Uint32 Function(ffi.Pointer<ffi.Opaque>)>(isLeaf: true, symbol: 'icu4x_Date_day_of_month_mv1')
+@ffi.Native<ffi.Uint8 Function(ffi.Pointer<ffi.Opaque>)>(isLeaf: true, symbol: 'icu4x_Date_day_of_month_mv1')
 // ignore: non_constant_identifier_names
 external int _icu4x_Date_day_of_month_mv1(ffi.Pointer<ffi.Opaque> self);
 
@@ -279,7 +279,7 @@ external int _icu4x_Date_day_of_month_mv1(ffi.Pointer<ffi.Opaque> self);
 external int _icu4x_Date_day_of_week_mv1(ffi.Pointer<ffi.Opaque> self);
 
 @meta.RecordUse()
-@ffi.Native<ffi.Uint32 Function(ffi.Pointer<ffi.Opaque>, ffi.Int32)>(isLeaf: true, symbol: 'icu4x_Date_week_of_month_mv1')
+@ffi.Native<ffi.Uint8 Function(ffi.Pointer<ffi.Opaque>, ffi.Int32)>(isLeaf: true, symbol: 'icu4x_Date_week_of_month_mv1')
 // ignore: non_constant_identifier_names
 external int _icu4x_Date_week_of_month_mv1(ffi.Pointer<ffi.Opaque> self, int firstWeekday);
 
diff --git a/ffi/capi/bindings/dart/DateTime.g.dart b/ffi/capi/bindings/dart/DateTime.g.dart
index 68ccd654f3..aac5ccbbe1 100644
--- a/ffi/capi/bindings/dart/DateTime.g.dart
+++ b/ffi/capi/bindings/dart/DateTime.g.dart
@@ -360,7 +360,7 @@ external int _icu4x_DateTime_nanosecond_mv1(ffi.Pointer<ffi.Opaque> self);
 external int _icu4x_DateTime_day_of_year_mv1(ffi.Pointer<ffi.Opaque> self);
 
 @meta.RecordUse()
-@ffi.Native<ffi.Uint32 Function(ffi.Pointer<ffi.Opaque>)>(isLeaf: true, symbol: 'icu4x_DateTime_day_of_month_mv1')
+@ffi.Native<ffi.Uint8 Function(ffi.Pointer<ffi.Opaque>)>(isLeaf: true, symbol: 'icu4x_DateTime_day_of_month_mv1')
 // ignore: non_constant_identifier_names
 external int _icu4x_DateTime_day_of_month_mv1(ffi.Pointer<ffi.Opaque> self);
 
@@ -370,7 +370,7 @@ external int _icu4x_DateTime_day_of_month_mv1(ffi.Pointer<ffi.Opaque> self);
 external int _icu4x_DateTime_day_of_week_mv1(ffi.Pointer<ffi.Opaque> self);
 
 @meta.RecordUse()
-@ffi.Native<ffi.Uint32 Function(ffi.Pointer<ffi.Opaque>, ffi.Int32)>(isLeaf: true, symbol: 'icu4x_DateTime_week_of_month_mv1')
+@ffi.Native<ffi.Uint8 Function(ffi.Pointer<ffi.Opaque>, ffi.Int32)>(isLeaf: true, symbol: 'icu4x_DateTime_week_of_month_mv1')
 // ignore: non_constant_identifier_names
 external int _icu4x_DateTime_week_of_month_mv1(ffi.Pointer<ffi.Opaque> self, int firstWeekday);
 
diff --git a/ffi/capi/bindings/dart/IsoDate.g.dart b/ffi/capi/bindings/dart/IsoDate.g.dart
index b0695f21d1..ce6ebf802e 100644
--- a/ffi/capi/bindings/dart/IsoDate.g.dart
+++ b/ffi/capi/bindings/dart/IsoDate.g.dart
@@ -205,7 +205,7 @@ external ffi.Pointer<ffi.Opaque> _icu4x_IsoDate_to_any_mv1(ffi.Pointer<ffi.Opaqu
 external int _icu4x_IsoDate_day_of_year_mv1(ffi.Pointer<ffi.Opaque> self);
 
 @meta.RecordUse()
-@ffi.Native<ffi.Uint32 Function(ffi.Pointer<ffi.Opaque>)>(isLeaf: true, symbol: 'icu4x_IsoDate_day_of_month_mv1')
+@ffi.Native<ffi.Uint8 Function(ffi.Pointer<ffi.Opaque>)>(isLeaf: true, symbol: 'icu4x_IsoDate_day_of_month_mv1')
 // ignore: non_constant_identifier_names
 external int _icu4x_IsoDate_day_of_month_mv1(ffi.Pointer<ffi.Opaque> self);
 
@@ -215,7 +215,7 @@ external int _icu4x_IsoDate_day_of_month_mv1(ffi.Pointer<ffi.Opaque> self);
 external int _icu4x_IsoDate_day_of_week_mv1(ffi.Pointer<ffi.Opaque> self);
 
 @meta.RecordUse()
-@ffi.Native<ffi.Uint32 Function(ffi.Pointer<ffi.Opaque>, ffi.Int32)>(isLeaf: true, symbol: 'icu4x_IsoDate_week_of_month_mv1')
+@ffi.Native<ffi.Uint8 Function(ffi.Pointer<ffi.Opaque>, ffi.Int32)>(isLeaf: true, symbol: 'icu4x_IsoDate_week_of_month_mv1')
 // ignore: non_constant_identifier_names
 external int _icu4x_IsoDate_week_of_month_mv1(ffi.Pointer<ffi.Opaque> self, int firstWeekday);
 
diff --git a/ffi/capi/bindings/dart/IsoDateTime.g.dart b/ffi/capi/bindings/dart/IsoDateTime.g.dart
index a07c815174..837b68bf8a 100644
--- a/ffi/capi/bindings/dart/IsoDateTime.g.dart
+++ b/ffi/capi/bindings/dart/IsoDateTime.g.dart
@@ -323,7 +323,7 @@ external int _icu4x_IsoDateTime_nanosecond_mv1(ffi.Pointer<ffi.Opaque> self);
 external int _icu4x_IsoDateTime_day_of_year_mv1(ffi.Pointer<ffi.Opaque> self);
 
 @meta.RecordUse()
-@ffi.Native<ffi.Uint32 Function(ffi.Pointer<ffi.Opaque>)>(isLeaf: true, symbol: 'icu4x_IsoDateTime_day_of_month_mv1')
+@ffi.Native<ffi.Uint8 Function(ffi.Pointer<ffi.Opaque>)>(isLeaf: true, symbol: 'icu4x_IsoDateTime_day_of_month_mv1')
 // ignore: non_constant_identifier_names
 external int _icu4x_IsoDateTime_day_of_month_mv1(ffi.Pointer<ffi.Opaque> self);
 
@@ -333,7 +333,7 @@ external int _icu4x_IsoDateTime_day_of_month_mv1(ffi.Pointer<ffi.Opaque> self);
 external int _icu4x_IsoDateTime_day_of_week_mv1(ffi.Pointer<ffi.Opaque> self);
 
 @meta.RecordUse()
-@ffi.Native<ffi.Uint32 Function(ffi.Pointer<ffi.Opaque>, ffi.Int32)>(isLeaf: true, symbol: 'icu4x_IsoDateTime_week_of_month_mv1')
+@ffi.Native<ffi.Uint8 Function(ffi.Pointer<ffi.Opaque>, ffi.Int32)>(isLeaf: true, symbol: 'icu4x_IsoDateTime_week_of_month_mv1')
 // ignore: non_constant_identifier_names
 external int _icu4x_IsoDateTime_week_of_month_mv1(ffi.Pointer<ffi.Opaque> self, int firstWeekday);
 
diff --git a/ffi/capi/bindings/dart/WeekOf.g.dart b/ffi/capi/bindings/dart/WeekOf.g.dart
index 9174183245..21ff745dae 100644
--- a/ffi/capi/bindings/dart/WeekOf.g.dart
+++ b/ffi/capi/bindings/dart/WeekOf.g.dart
@@ -3,7 +3,7 @@
 part of 'lib.g.dart';
 
 final class _WeekOfFfi extends ffi.Struct {
-  @ffi.Uint16()
+  @ffi.Uint8()
   external int week;
   @ffi.Int32()
   external int unit;
diff --git a/ffi/capi/bindings/js/WeekOf.mjs b/ffi/capi/bindings/js/WeekOf.mjs
index 28aa35f60c..cb6397cdde 100644
--- a/ffi/capi/bindings/js/WeekOf.mjs
+++ b/ffi/capi/bindings/js/WeekOf.mjs
@@ -38,7 +38,7 @@ export class WeekOf {
         appendArrayMap,
         forcePadding
     ) {
-        return [this.#week, ...diplomatRuntime.maybePaddingFields(forcePadding, 1 /* x i16 */), this.#unit.ffiValue]
+        return [this.#week, ...diplomatRuntime.maybePaddingFields(forcePadding, 3 /* x i8 */), this.#unit.ffiValue]
     }
 
     _writeToArrayBuffer(
@@ -48,7 +48,7 @@ export class WeekOf {
         appendArrayMap,
         forcePadding
     ) {
-        diplomatRuntime.writeToArrayBuffer(arrayBuffer, offset + 0, this.#week, Uint16Array);
+        diplomatRuntime.writeToArrayBuffer(arrayBuffer, offset + 0, this.#week, Uint8Array);
         diplomatRuntime.writeToArrayBuffer(arrayBuffer, offset + 4, this.#unit.ffiValue, Int32Array);
     }
 
@@ -58,7 +58,7 @@ export class WeekOf {
     // This method does not attempt to handle any dependencies between lifetimes, the caller
     // should handle this when constructing edge arrays.
     #fromFFI(ptr) {
-        const weekDeref = (new Uint16Array(wasm.memory.buffer, ptr, 1))[0];
+        const weekDeref = (new Uint8Array(wasm.memory.buffer, ptr, 1))[0];
         this.#week = weekDeref;
         const unitDeref = diplomatRuntime.enumDiscriminant(wasm, ptr + 4);
         this.#unit = new WeekRelativeUnit(diplomatRuntime.internalConstructor, unitDeref);
diff --git a/ffi/capi/src/date.rs b/ffi/capi/src/date.rs
index e2336ab446..ba54b857ca 100644
--- a/ffi/capi/src/date.rs
+++ b/ffi/capi/src/date.rs
@@ -81,7 +81,7 @@ pub mod ffi {
         /// Returns the 1-indexed day in the month for this date
         #[diplomat::rust_link(icu::calendar::Date::day_of_month, FnInStruct)]
         #[diplomat::attr(auto, getter)]
-        pub fn day_of_month(&self) -> u32 {
+        pub fn day_of_month(&self) -> u8 {
             self.0.day_of_month().0
         }
 
@@ -102,7 +102,7 @@ pub mod ffi {
             FnInStruct,
             hidden
         )]
-        pub fn week_of_month(&self, first_weekday: IsoWeekday) -> u32 {
+        pub fn week_of_month(&self, first_weekday: IsoWeekday) -> u8 {
             self.0.week_of_month(first_weekday.into()).0
         }
 
@@ -251,7 +251,7 @@ pub mod ffi {
         /// Returns the 1-indexed day in the month for this date
         #[diplomat::rust_link(icu::calendar::Date::day_of_month, FnInStruct)]
         #[diplomat::attr(auto, getter)]
-        pub fn day_of_month(&self) -> u32 {
+        pub fn day_of_month(&self) -> u8 {
             self.0.day_of_month().0
         }
 
@@ -272,7 +272,7 @@ pub mod ffi {
             FnInStruct,
             hidden
         )]
-        pub fn week_of_month(&self, first_weekday: IsoWeekday) -> u32 {
+        pub fn week_of_month(&self, first_weekday: IsoWeekday) -> u8 {
             self.0.week_of_month(first_weekday.into()).0
         }
 
diff --git a/ffi/capi/src/datetime.rs b/ffi/capi/src/datetime.rs
index 306fed9320..cf6dd7e0af 100644
--- a/ffi/capi/src/datetime.rs
+++ b/ffi/capi/src/datetime.rs
@@ -153,7 +153,7 @@ pub mod ffi {
         /// Returns the 1-indexed day in the month for this date
         #[diplomat::rust_link(icu::calendar::Date::day_of_month, FnInStruct)]
         #[diplomat::attr(auto, getter)]
-        pub fn day_of_month(&self) -> u32 {
+        pub fn day_of_month(&self) -> u8 {
             self.0.date.day_of_month().0
         }
 
@@ -174,7 +174,7 @@ pub mod ffi {
             FnInStruct,
             hidden
         )]
-        pub fn week_of_month(&self, first_weekday: IsoWeekday) -> u32 {
+        pub fn week_of_month(&self, first_weekday: IsoWeekday) -> u8 {
             self.0.date.week_of_month(first_weekday.into()).0
         }
 
@@ -386,7 +386,7 @@ pub mod ffi {
         /// Returns the 1-indexed day in the month for this date
         #[diplomat::rust_link(icu::calendar::Date::day_of_month, FnInStruct)]
         #[diplomat::attr(auto, getter)]
-        pub fn day_of_month(&self) -> u32 {
+        pub fn day_of_month(&self) -> u8 {
             self.0.date.day_of_month().0
         }
 
@@ -407,7 +407,7 @@ pub mod ffi {
             FnInStruct,
             hidden
         )]
-        pub fn week_of_month(&self, first_weekday: IsoWeekday) -> u32 {
+        pub fn week_of_month(&self, first_weekday: IsoWeekday) -> u8 {
             self.0.date.week_of_month(first_weekday.into()).0
         }
 
diff --git a/ffi/capi/src/week.rs b/ffi/capi/src/week.rs
index 4d643a8bf5..4c7c2e3b02 100644
--- a/ffi/capi/src/week.rs
+++ b/ffi/capi/src/week.rs
@@ -24,7 +24,7 @@ pub mod ffi {
     #[diplomat::rust_link(icu::calendar::week::WeekOf, Struct)]
     #[diplomat::out]
     pub struct WeekOf {
-        pub week: u16,
+        pub week: u8,
         pub unit: WeekRelativeUnit,
     }
     /// A Week calculator, useful to be passed in to `week_of_year()` on Date and DateTime types