Time Zone Converter
Convert a date and time between time zones, or compare several cities at a glance — built for scheduling calls, flights, and meetings across time zones without doing the math by hand.
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Why the same moment shows two different dates
Time zones don't just shift the hour — they can shift the date too. When it's 11pm Monday in Los Angeles, it's already 7am Tuesday in London. This tool always compares a single, specific instant, so if the converted time falls on a different calendar day than your starting point, it's labeled “+1 day” or “-1 day” — easy to miss if you're just glancing at the clock face.
Daylight saving time is the other trap: not every country observes it, and the ones that do don't switch on the same date. A “UTC+8” label today might be “UTC+9” in six months for the same city. Rather than hardcoding offsets, this tool asks your browser for the correct rule for the exact date you're converting, so it stays accurate across DST transitions.
By default the “From” zone is detected from your device, and the target list starts with a few common zones you can swap out for any of roughly 400 IANA time zones — search by city or region, add as many as you're coordinating with.
Frequently asked questions
Why does it say “+1 day” next to one of the times?
Because the converted time falls on a different calendar date than the one you started from. If it's 10pm on the 5th in your zone, it might already be 6am on the 6th somewhere else — the “+1 day” (or “-1 day”) label makes sure you don't schedule something on the wrong day by mistake.
How does it handle daylight saving time?
It doesn't use a fixed offset — it asks your browser's timezone database for the actual UTC offset on the specific date you entered, which already accounts for each region's own DST start and end dates. That's why the same city can show a different offset depending on the date you pick.
Where does the “detected” time zone come from?
Two places: your device's own system settings (used as the default “From” zone), and, separately, your approximate location from your IP address, shown as a quick suggestion if it differs from your device's setting — handy if you're traveling and haven't updated your laptop's clock yet.
Is anything I enter here sent to a server?
The date, time, and zone conversions all happen in your browser using its built-in time zone data — nothing about what you type is sent anywhere. Only the one-time IP-based time zone suggestion involves a request, and it doesn't include anything you've entered.