Chile Standard Time (CLT)

Chile Standard Time (CLT) operates at UTC−4 hours and is observed across most of mainland Chile during the winter months, generally from April to September. Sometimes referred to as "Chile Winter Time," CLT helps align schedules with seasonal daylight patterns and shifts to Chile Summer Time (CLST, UTC−3) during the summer.

Importance and Global Use of CLT

CLT is essential for managing consistent schedules, education, business operations, and transportation throughout most of Chile during the winter season. Its stable UTC−4 offset ensures reliable timekeeping for residents, public services, and industries across the country's major urban areas, including Santiago and Valparaíso.

Internationally, CLT supports Chile's coordination with global partners in North America, Europe, and other parts of South America. By providing a predictable standard time, CLT facilitates aviation, maritime traffic, diplomatic activities, and international trade during the southern hemisphere winter months.

Where and When CLT is used worldwide

South America

South American countries using CLT during winter and CLST during summer:

• Chile – except the following regions:
  • Aysén Region, which uses CLST time zone
  • Isla de Pascua (Easter Island), which uses EAST/EASST time zones
  • Magallanes and the Chilean Antarctic Region, which use CLST time zone

Other Time Zones in UTC -4

Other time zones share the same offset as Chile Standard Time (CLT), but are known by different names. While their clocks align, they may represent different regions or countries based on local time zone definitions.

• Amazon Time – AMT
• Atlantic Standard Time – AST
• Bolivia Time – BOT
• Cuba Daylight Time – CDT
• Eastern Daylight Time – EDT
• Guyana Time – GYT
• Venezuelan Standard Time – VET