if they're zero and the strings 'midnight' and 'noon' if appropriate.
Examples: '1 a.m.', '1:30 p.m.', 'midnight', 'noon', '12:30 p.m.'
Proprietary extension.
Time zone offset in seconds (i.e. '-43200' to '43200'). The offset for timezones west of UTC is always negative, and for those east of UTC is always positive.