Technical Specifications & Standards
Official chronometric properties, ISO standards, and international database registry identifiers for Chile Standard Time:
Daylight Saving Time (DST) Transitions
⬆️ Spring Forward (Clocks Advance)
First Saturday in September at 24:00 / midnight (Continental clocks advance to CLST)
⬇️ Fall Back (Clocks Return)
First Saturday in April at 24:00 / midnight (Continental clocks return to CLT)
Observing Jurisdictions & Subdivisions
2 Sovereign NationsSovereign nations, administrative subdivisions, and regional territories officially operating under CLT:
Regional Subdivisions & Territory Details
Financial Markets & Trading Hours
Santiago equity trading and global copper contracts synchronize closely with the opening bell on the New York Stock Exchange and the London Metal Exchange.
Local Hours: 09:30 - 16:00 CLT
UTC Window: 13:30 - 20:00 UTC
Major Cities in CLT
Primary metropolitan centers and financial hubs observing this time zone:
Adoption History & Astronomical Facts
Year Established: 1890
First regulated through the National Astronomical Observatory in 1890. In 2015, the Chilean government attempted to abolish winter time permanently and stay on UTC-3, but mid-winter sunrises as late as 08:45 AM caused widespread exhaustion and safety concerns for schoolchildren in Santiago, forcing the restoration of winter standard time in 2016.
Because the southernmost region of Magallanes and Chilean Antarctica (centered on Punta Arenas) experiences extreme winter darkness, the provincial legislature opted out of the winter clock change in 2017, staying on UTC-3 year-round.
Frequently Asked Questions about CLT
What is the difference between CLT and CLST?
CLT (Chile Standard Time, UTC-4) is the winter standard time used between April and September. CLST (Chile Summer Time, UTC-3) is the daylight saving time used during the Southern Hemisphere summer between September and April.
Do all parts of Chile observe CLT in the winter?
No. The southern Magallanes region around Punta Arenas stays on UTC-3 all year. Easter Island (Rapa Nui) is situated in the Pacific Ocean and uses UTC-6 during winter.
On which day does Chile change its clocks?
Under current law, Chile changes its clocks on the first Saturday of April (falling back at midnight) and the first Saturday of September (springing forward at midnight).