From c4e1dd00610b7aa800230e22a29dc0fafb22a3f4 Mon Sep 17 00:00:00 2001
From: Robert Bastian <robertbastian@unicode.org>
Date: Fri, 11 Oct 2024 14:04:15 -0700
Subject: [PATCH 1/2] secondss

---
 components/datetime/src/time_zone.rs  | 17 ++++++++++++++++-
 components/datetime/tests/datetime.rs | 18 +++++++++++++++++-
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/components/datetime/src/time_zone.rs b/components/datetime/src/time_zone.rs
index b8fa1beb2bf..3e26a42f8ba 100644
--- a/components/datetime/src/time_zone.rs
+++ b/components/datetime/src/time_zone.rs
@@ -402,7 +402,10 @@ impl FormatOffset for LocalizedOffsetFormat {
                         )
                         .write_to(sink)?;
 
-                    if self.length == FieldLength::Wide || self.offset.has_minutes() {
+                    if self.length == FieldLength::Wide
+                        || self.offset.has_minutes()
+                        || self.offset.has_seconds()
+                    {
                         sink.write_char(self.separator)?;
                         self.fdf
                             .format(
@@ -414,6 +417,18 @@ impl FormatOffset for LocalizedOffsetFormat {
                             .write_to(sink)?;
                     }
 
+                    if self.offset.has_seconds() {
+                        sink.write_char(self.separator)?;
+                        self.fdf
+                            .format(
+                                &FixedDecimal::from(
+                                    (self.offset.offset_seconds() % 3600).unsigned_abs(),
+                                )
+                                .padded_start(2),
+                            )
+                            .write_to(sink)?;
+                    }
+
                     Ok(())
                 }
             }
diff --git a/components/datetime/tests/datetime.rs b/components/datetime/tests/datetime.rs
index 801ef332769..e0ced66ec90 100644
--- a/components/datetime/tests/datetime.rs
+++ b/components/datetime/tests/datetime.rs
@@ -37,7 +37,7 @@ use icu_locale_core::{
     locale, LanguageIdentifier, Locale,
 };
 use icu_provider::prelude::*;
-use icu_timezone::{CustomTimeZone, CustomZonedDateTime};
+use icu_timezone::{CustomTimeZone, CustomZonedDateTime, UtcOffset};
 use patterns::{
     dayperiods::{DayPeriodExpectation, DayPeriodTests},
     time_zones::{TimeZoneExpectation, TimeZoneFormatterConfig, TimeZoneTests},
@@ -471,6 +471,22 @@ fn test_time_zone_format_configs() {
     }
 }
 
+#[test]
+fn test_time_zone_format_offset_seconds() {
+    use icu_datetime::{
+        neo_marker::NeoTimeZoneOffsetMarker, neo_skeleton::NeoSkeletonLength, NeverCalendar,
+    };
+
+    let time_zone =
+        CustomTimeZone::new_with_offset(UtcOffset::try_from_offset_seconds(12).unwrap());
+    let tzf = TypedNeoFormatter::<NeverCalendar, _>::try_new(
+        &locale!("en").into(),
+        NeoTimeZoneOffsetMarker::with_length(NeoSkeletonLength::Medium),
+    )
+    .unwrap();
+    assert_try_writeable_eq!(tzf.format(&time_zone), "GMT+0:00:12",);
+}
+
 #[test]
 fn test_time_zone_format_offset_not_set_debug_assert_panic() {
     use icu_datetime::{

From 2bab5b960706f69022a0aca8a1b4ab29d5f91195 Mon Sep 17 00:00:00 2001
From: Robert Bastian <4706271+robertbastian@users.noreply.github.com>
Date: Mon, 14 Oct 2024 08:40:20 -0700
Subject: [PATCH 2/2] Update components/datetime/src/time_zone.rs

Co-authored-by: Shane F. Carr <shane@unicode.org>
---
 components/datetime/src/time_zone.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/datetime/src/time_zone.rs b/components/datetime/src/time_zone.rs
index 3e26a42f8ba..fce6ec0fea6 100644
--- a/components/datetime/src/time_zone.rs
+++ b/components/datetime/src/time_zone.rs
@@ -422,7 +422,7 @@ impl FormatOffset for LocalizedOffsetFormat {
                         self.fdf
                             .format(
                                 &FixedDecimal::from(
-                                    (self.offset.offset_seconds() % 3600).unsigned_abs(),
+                                    (self.offset.offset_seconds() % 60).unsigned_abs(),
                                 )
                                 .padded_start(2),
                             )