How timezone conversion works

A timezone is a region's set of UTC offset rules, including daylight saving transitions. Converting between zones means interpreting your wall-clock time in the source zone to find the absolute instant, then expressing that instant in the target zone's rules. This tool uses the IANA timezone database built into your browser, so conversions are DST-aware and always current.

Tip: for machine-to-machine communication, store and transmit epoch timestamps or ISO 8601 with an explicit offset, and convert to a local zone only at display time. See current time in common zones such as UTC, US Eastern or Japan.