inUtc method
Returns the mapping of this local date/time within DateTimeZone.utc.
As UTC is a fixed time zone, there is no chance that this local date/time is ambiguous or skipped.
Returns: The result of mapping this local date/time in UTC.
Implementation
ZonedDateTime inUtc() =>
// Use the internal constructors to avoid validation. We know it will be fine.
IZonedDateTime.trusted(IOffsetDateTime.fullTrust(this, Offset.zero), DateTimeZone.utc);