Chile uses Chile Standard Time (CLT, UTC−4) in winter and Chile Summer Time (CLST, UTC−3) in summer. Chile's seasons are reversed relative to the Northern Hemisphere — summer in Chile runs from December to March.
DST in 2025: clocks spring forward on Saturday night 4 October 2025 (start of Chilean spring) and fall back on Saturday night 5 April 2025 (start of Chilean autumn). This puts Santiago and other Chilean cities on UTC−3 during the Southern Hemisphere summer.
The Magallanes Region (Punta Arenas) permanently uses UTC−3, without seasonal changes — it was moved to permanent 'summer time' in 2016. Easter Island (Isla de Pascua) uses a separate offset: UTC−6 standard / UTC−5 during summer time.
Key gaps from Santiago: New York (EST) is 1–2 hours ahead depending on season. London is 3–4 hours ahead. Buenos Aires (UTC−3) shares roughly the same time during Chilean summer.