Time Zone Converter

How to use the time zone converter

1. Pick a Date and a Time. The Now button fills in the current date and time in the source zone.
2. In From time zone, type a city or a zone name, such as “Paris”, “New York” or “Asia/Tokyo”, and pick it from the list. Your own time zone is selected by default.
3. Under Convert to, read the same moment in each target zone, with its UTC offset, its abbreviation when there is one, whether daylight saving time applies, and whether it falls on the previous or next day.
4. Change any target by typing in its field, remove it with Remove, or add more with Add a time zone. Your list of target zones is remembered in this browser.

How the conversion works

This tool uses the time zone database built into your browser (the IANA tz database, also used by operating systems and most programming languages) through the standard Intl JavaScript API. Each zone, such as Europe/Paris or America/Toronto, contains the full history of its UTC offsets and daylight saving time rules. The time you enter is first turned into an exact moment, then shown on the local clock of each target zone.

Using zone names rather than fixed offsets matters: “UTC+1” is Paris in winter, but Paris is at UTC+2 in summer. With a named zone, the correct offset is chosen automatically for the date you enter.

Daylight saving time pitfalls

Daylight saving time (DST) causes most time zone mistakes, and this tool handles them for you:

• Different switch dates. The United States and Canada move their clocks forward on the second Sunday of March, while the European Union does it on the last Sunday of March. For two or three weeks, New York is only 5 hours behind Paris instead of 6. The same gap appears in autumn, between the last Sunday of October in Europe and the first Sunday of November in North America.
• Times that don’t exist. When clocks jump forward, for example from 2:00 to 3:00 in Paris, 2:30 never happens. The tool warns you and uses the time just after the jump.
• Times that happen twice. When clocks go back, 2:30 occurs twice. The tool warns you and uses the first occurrence.
• Southern hemisphere. Sydney, Santiago or Auckland observe summer time from about October to April, the opposite of Europe.
• Zones without DST. Tokyo, Beijing, Mumbai, Dubai and most of Africa don’t change their clocks at all.

Some zones also have offsets that aren’t whole hours: India is at UTC+05:30, Nepal at UTC+05:45 and Newfoundland at UTC−03:30 (−02:30 in summer).

Tips for scheduling across time zones

When planning a meeting, add all participants’ cities as target zones and move the time until everyone falls within working hours. Check the day label: a late afternoon call in California is already the next morning in Tokyo. For invitations, mention the time with its zone or UTC offset, or send a calendar invite, which converts the time for each guest.