LibTimeZone: Handle time zones which begin the year in daylight savings

lanmonster · Jan 25, 2022 · 1f051a8 · 1f051a8
1 parent 7103012
commit 1f051a8
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/Meta/Lagom/Tools/CodeGenerators/LibTimeZone/GenerateTimeZoneData.cpp b/Meta/Lagom/Tools/CodeGenerators/LibTimeZone/GenerateTimeZoneData.cpp
@@ -545,8 +545,14 @@ static Offset get_active_dst_offset(TimeZoneOffset const& time_zone_offset, AK::
  auto standard_time_in_effect = offsets[0]->time_in_effect(time);
  auto daylight_time_in_effect = offsets[1]->time_in_effect(time);
 
- if ((time < daylight_time_in_effect) || (time >= standard_time_in_effect))
- return { offsets[0]->offset, InDST::No };
+ if (daylight_time_in_effect < standard_time_in_effect) {
+ if ((time < daylight_time_in_effect) || (time >= standard_time_in_effect))
+ return { offsets[0]->offset, InDST::No };
+ } else {
+ if ((time >= standard_time_in_effect) && (time < daylight_time_in_effect))
+ return { offsets[0]->offset, InDST::No };
+ }
+
  return { offsets[1]->offset, InDST::Yes };
 }
 

diff --git a/Tests/LibTimeZone/TestTimeZone.cpp b/Tests/LibTimeZone/TestTimeZone.cpp
@@ -147,6 +147,11 @@ TEST_CASE(get_time_zone_offset_with_dst)
  test_offset("Europe/Moscow"sv, -1596412800, offset(+1, 4, 31, 19), Yes); // Sunday, June 1, 1919 12:00:00 AM
  test_offset("Europe/Moscow"sv, -1592611200, offset(+1, 4, 00, 00), Yes); // Tuesday, July 15, 1919 12:00:00 AM
  test_offset("Europe/Moscow"sv, -1589068800, offset(+1, 3, 00, 00), No); // Monday, August 25, 1919 12:00:00 AM
+
+ // Paraguay begins the year in DST.
+ test_offset("America/Asuncion"sv, 1642558528, offset(-1, 3, 00, 00), Yes); // Wednesday, January 19, 2022 2:15:28 AM
+ test_offset("America/Asuncion"sv, 1663553728, offset(-1, 4, 00, 00), No); // Monday, September 19, 2022 2:15:28 AM
+ test_offset("America/Asuncion"sv, 1671453238, offset(-1, 3, 00, 00), Yes); // Monday, December 19, 2022 12:33:58 PM
 }
 
 TEST_CASE(get_named_time_zone_offsets)