util_comp_time_to_zone

Converts the time/date property prop_kind to to_zone.

When such property does not exist, or does not contain DATE nor DATE-TIME value, then the function returns -1 and no output argument is set.

The vcalendar is used to get the timezone for the property, if provided, otherwise the timezone is tried to be found in the tz_cache. If neither can get it, the iCal builtin timezones are checked. When the set timezone cannot be found, floating time is used (which can be almost always wrong).

Note: this uses get_first_property, thus it cannot be used in case any upper caller uses it too at the same time.

Parameters:

icomp	an Component to get the property from
prop_kind	an PropertyKind of the property to read
to_zone	an Timezone to convert the time to, or null for UTC
vcalendar	an optional VCALENDAR component with timezones for the icomp, or null when not available
tz_cache	an TimezoneCache to use to read the time zones from, or null if not available
out_itt	return location for the converted time as Time, or null when not requested

Returns:

property's time converted into to_zone, or -1, when the conversion was not possible.