It is one of only two official time zones with a 45-minute increment from UTC. Nepal Time is the other time zone that keeps its offset at UTC+05:45.
During summer daylight saving time is observed and clocks are advanced one hour. Chatham Daylight Time (CHADT) is 13 hours 45 minutes ahead of UTC, 45 minutes ahead of New Zealand Daylight Time (NZDT). Currently daylight saving time runs from the last Sunday in September to the first Sunday in April.