タイムゾーン変換

This converter takes a time in one zone and shows it in major cities worldwide, so you do not have to do the arithmetic in your head.

It is built for the everyday problem of coordinating across countries: scheduling a call with a colleague abroad, catching a livestream at the right local moment, or working out when a deadline in another zone actually falls for you.

Everything runs in your browser using your system's time zone data, so nothing you enter is uploaded.

Daylight saving is the part people get wrong, and the tool handles it for you. Conversions use your device's time zone database, so the shifts are applied correctly for the exact date and city, not just a fixed offset.

It shows a selection of major cities across every continent, from Honolulu to Auckland, with UTC included as a neutral reference point that never changes with the seasons.

Because offsets change with daylight saving, the same city can be an hour different depending on the date, which is why entering the exact day matters when the timing is tight.