fix timezone conversion

sdk/identity/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "azure_identity"
-version = "0.16.1"
+version = "0.16.2"
 description = "Rust wrappers around Microsoft Azure REST APIs - Azure identity helper crate"
 readme = "README.md"
 authors = ["Microsoft Corp."]

sdk/identity/src/token_credentials/azure_cli_credentials.rs

@@ -39,8 +39,25 @@ mod az_cli_date_format {
         };
 
         let as_unix = as_utc.unix_timestamp();
+
+        // if we can't find the local time type, just return the UTC date
+        let Ok(local_time_type) = tz.find_local_time_type(as_unix) else {
+            return as_utc;
+        };
+
         // if we can't convert the unix timestamp to a DateTime, just return the UTC date
-        let Ok(date) = tz::DateTime::from_timespec(as_unix, 0, tz.as_ref()) else {
+        let date = as_utc.date();
+        let time = as_utc.time();
+        let Ok(date) = tz::DateTime::new(
+            date.year(),
+            u8::from(date.month()),
+            date.day(),
+            time.hour(),
+            time.minute(),
+            time.second(),
+            time.nanosecond(),
+            *local_time_type,
+        ) else {
             return as_utc;
         };
 
@@ -174,6 +191,32 @@ mod tests {
             az_cli_date_format::parse(expires_on)?,
             az_cli_date_format::assume_local(&datetime!(2022-07-30 12:12:53.919110))
         );
+
+        Ok(())
+    }
+
+    #[cfg(unix)]
+    #[test]
+    /// test the timezone conversion works as expected on unix platforms
+    ///
+    /// To validate the timezone conversion works as expected, this test
+    /// temporarily sets the timezone to PST, performs the check, then resets
+    /// the TZ enviornment variable.
+    fn check_timezone() -> azure_core::Result<()> {
+        let before = std::env::var("TZ").ok();
+        std::env::set_var("TZ", "PST");
+        let expires_on = "2022-07-30 12:12:53.919110";
+        let result = az_cli_date_format::parse(expires_on);
+
+        if let Some(before) = before {
+            std::env::set_var("TZ", before);
+        } else {
+            std::env::remove_var("TZ");
+        }
+
+        let expected = datetime!(2022-07-30 16:12:53).assume_utc();
+        assert_eq!(expected, result?);
+
         Ok(())
     }
 }