Time zone · Americas
CLST
Chile Summer Time
Chile Summer Time (CLST) is UTC-03:00, the daylight saving time Santiago and most of mainland Chile use from early September to early April, one hour ahead of Chile Standard Time (UTC-04:00).
Monday, October 26, 2026
Current offset
UTC-03:00
Daylight · -03
Daylight saving
Active
Reverts 3 Apr 2027
IANA zones
1
1 observe DST, 0 don't
DST offset
—
No summer variant
About CLST
Standard time, with a summer shift.
Chile Summer Time (CLST) is UTC-03:00, the daylight saving time Santiago and most of mainland Chile use from early September to early April, one hour ahead of Chile Standard Time (UTC-04:00).
IANA zones · the technical identifiers
The zone that resolve to CLST.
For software, always store the IANA identifier — never the abbreviation alone. The database keeps these zones distinct because their rules can, and historically did, diverge.
Cities across CLST
Local time, city by city.
3 cities
Where CLST is used
One country.
Same offset · UTC-03:00
Other zones at UTC-03:00 right now.
These named zones share CLST's offset today. When daylight saving rules differ, they drift apart for part of the year.
Convert
CLST to the world's clocks.
Frequently asked questions
Common questions about CLST, daylight saving, and how to handle it in software. Can't find what you need? Email [email protected].
- What does CLST stand for?
- CLST is the abbreviation for Chile Summer Time, the UTC-03:00 advanced offset Santiago uses during daylight saving to extend evening daylight.
- When does Santiago observe CLST?
- From early September to early April, when Santiago moves from its standard UTC-04:00 to UTC-03:00.
- When do Santiago’s clocks change?
- Clocks move forward to CLST in early September and back to standard time in early April, both at midnight between Saturday and Sunday.
- How often does Santiago move between offsets?
- Twice a year: forward from UTC-04:00 to UTC-03:00 in early September and back in early April, on dates set by Chilean decree.
- Is the CLST schedule likely to change?
- Chile has modified its daylight-saving rules in recent years, so public announcements may shift the exact dates or abolish the practice altogether.
- How does CLST affect global coordination?
- During CLST, Santiago is ahead of New York and three to four hours behind London, and because the Northern Hemisphere changes clocks on different dates, the gaps shift several times a year.
- Is Easter Island on the same schedule?
- Not quite. Easter Island is two hours behind Santiago all year (UTC-06:00 in winter, UTC-05:00 in summer), but it changes its clocks on the same dates.
- What puts CLST ahead of its standard time?
- During summer months, Santiago nudges clocks forward an hour to make use of longer daylight in the evening.
Source: IANA tzdb2026e · Reviewed
Free · Developer API
This time zone, as JSON.
Its defining offset, DST status and member counts, from one endpoint.
Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.
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