date: fix date get timezone error while set utc time (#6495)

src/uu/date/src/date.rs

@@ -227,11 +227,9 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
                 Box::new(iter)
             }
             DateSource::Human(relative_time) => {
-                // Get the current DateTime<FixedOffset> for things like "1 year ago"
-                let current_time = DateTime::<FixedOffset>::from(Local::now());
-                // double check the result is overflow or not of the current_time + relative_time
+                // Double check the result is overflow or not of the current_time + relative_time
                 // it may cause a panic of chrono::datetime::DateTime add
-                match current_time.checked_add_signed(relative_time) {
+                match now.checked_add_signed(relative_time) {
                     Some(date) => {
                         let iter = std::iter::once(Ok(date));
                         Box::new(iter)

tests/by-util/test_date.rs

@@ -141,6 +141,16 @@ fn test_date_utc() {
     }
 }
 
+#[test]
+fn test_date_utc_issue_6495() {
+    new_ucmd!()
+        .arg("-u")
+        .arg("-d")
+        .arg("@0")
+        .succeeds()
+        .stdout_is("Thu Jan  1 00:00:00 1970\n");
+}
+
 #[test]
 fn test_date_format_y() {
     let scene = TestScenario::new(util_name!());