What Is My Timezone?

What is a timezone?

A timezone is a region of the world that observes a uniform standard time. Timezones are defined as offsets from Coordinated Universal Time (UTC), the primary time standard by which the world regulates clocks and time. UTC offsets range from UTC−12:00 to UTC+14:00.

The IANA (Internet Assigned Numbers Authority) Time Zone Database, also known as the tz database or Olson database, is the most widely used system for timezone identification. It uses descriptive names like "Europe/Rome", "America/New_York", or "Asia/Tokyo" to identify timezones uniquely, accounting for historical changes and daylight saving time rules.

Major world timezones

• UTC−5 (EST) — Eastern Standard Time (New York, Toronto)
• UTC−8 (PST) — Pacific Standard Time (Los Angeles, Vancouver)
• UTC+0 (GMT) — Greenwich Mean Time (London, Dublin)
• UTC+1 (CET) — Central European Time (Rome, Paris, Berlin)
• UTC+8 (CST) — China Standard Time (Beijing, Singapore)
• UTC+9 (JST) — Japan Standard Time (Tokyo)

What is Daylight Saving Time (DST)?

Daylight Saving Time (DST) is the practice of advancing clocks by one hour during the warmer months so that darkness falls later in the day. Countries that observe DST typically move clocks forward in spring ("spring forward") and back in autumn ("fall back").

DST observation varies significantly by country. The United States and Canada observe DST, moving clocks forward on the second Sunday of March and back on the first Sunday of November. Most EU countries observe Summer Time, moving clocks on the last Sunday of March and October. Countries near the equator generally do not observe DST as daylight hours do not vary significantly throughout the year.

Your browser's Intl API automatically accounts for DST when reporting your UTC offset, so the offset shown on this page reflects whether DST is currently active in your timezone.