LibJS+LibTimeZone+LibUnicode: Indicate whether a time zone is in DST

Return whether the time zone is in DST during the provided time from
TimeZone::get_time_zone_offset,

2 files changed, 5 insertions, 4 deletions

diff --git a/Userland/Libraries/LibJS/Runtime/Date.cpp b/Userland/Libraries/LibJS/Runtime/Date.cpp
index 77c251350b..486aa00a43 100644
--- a/Userland/Libraries/LibJS/Runtime/Date.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Date.cpp
@@ -286,7 +286,8 @@ double local_tza(double time, [[maybe_unused]] bool is_utc, Optional<StringView>
 
     auto time_since_epoch = Value(time).is_finite_number() ? AK::Time::from_milliseconds(time) : AK::Time::max();
     auto maybe_offset = TimeZone::get_time_zone_offset(time_zone, time_since_epoch);
-    return maybe_offset.value_or(0) * 1000;
+
+    return maybe_offset.has_value() ? static_cast<double>(maybe_offset->seconds) * 1000 : 0;
 }
 
 // 21.4.1.8 LocalTime ( t ), https://tc39.es/ecma262/#sec-localtime
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp
index 6d604ae84e..8754e7f906 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp
@@ -175,10 +175,10 @@ i64 get_iana_time_zone_offset_nanoseconds(BigInt const& epoch_nanoseconds, Strin
     else
         time = Time::from_seconds(*seconds.to_base(10).to_int<i64>());
 
-    auto offset_seconds = ::TimeZone::get_time_zone_offset(*time_zone, time);
-    VERIFY(offset_seconds.has_value());
+    auto offset = ::TimeZone::get_time_zone_offset(*time_zone, time);
+    VERIFY(offset.has_value());
 
-    return *offset_seconds * 1'000'000'000;
+    return offset->seconds * 1'000'000'000;
 }
 
 // 11.6.5 GetIANATimeZoneNextTransition ( epochNanoseconds, timeZoneIdentifier ), https://tc39.es/proposal-temporal/#sec-temporal-getianatimezonenexttransition