Time Zone Converter
Convert a date and time between time zones and see day and night on a world map.
Type an IANA name, or click a city on the map.
Click a city to add or remove it. The shaded area is night at the selected time; the numbers along the bottom are nominal UTC offsets.
How it works
Pick a date and time, choose the zone it belongs to, and every zone in the list shows the same instant in its own wall-clock time, with the weekday, the UTC offset, a DST badge when daylight saving is in force, and a +1 day or -1 day marker when the date changes. The tool starts from your own zone and the current time.
Any IANA zone known to your browser can be added by name, such as America/Sao_Paulo or Asia/Kathmandu, and half-hour and quarter-hour offsets like India's UTC+05:30 and Nepal's UTC+05:45 are handled exactly. The arrow button on a row makes that zone the source while keeping the same instant, and Swap does the same for the first row.
The world map shades the half of the planet that is in darkness at the selected moment and marks the point where the sun is overhead, so you can see at a glance whether a colleague is likely to be awake. Click a city on the map to add or remove it; the numbers along the bottom are the nominal offsets of 15-degree bands, which real zone borders often follow only loosely.
Times that fall in a daylight saving transition are resolved the way calendars do. A time that happens twice when clocks go back uses the first occurrence, and a time skipped when clocks go forward, such as 02:30 on the day Europe moves to summer time, is moved forward by the gap and flagged in the status bar.
Frequently asked questions
- Does the converter account for daylight saving time?
- Yes. Offsets come from the time zone database built into your browser, so each zone uses the rules in force on the date you pick, including past and announced future changes. A DST badge marks the zones observing daylight saving at that moment.
- What is the difference between a time zone and a UTC offset?
- An offset such as UTC+01:00 is a fixed distance from UTC. A time zone such as Europe/Rome is a region with a history of offsets, which here alternates between UTC+01:00 in winter and UTC+02:00 in summer. Store the zone name, not the offset, when scheduling future events.
- Why is my city not in the list?
- Zones are named after one representative city, so Milan uses Europe/Rome and Barcelona uses Europe/Madrid. Type the name of the zone your city belongs to; the list suggests every IANA zone your browser supports.
- How accurate is the day and night shading?
- The sun position is computed from a standard astronomical approximation that is accurate to a fraction of a degree, which is far finer than the map can show. It does not draw twilight, so the edge of the shaded area is the moment of sunrise or sunset.
- Is anything sent to a server?
- No. The conversion uses the browser's Intl API and the map is drawn locally from bundled outlines, so the times and zones you enter never leave your device.