Find a time that works everywhere

• The first city is your reference. Drag the slider to choose a time of day there and every other clock follows.
• Click a city name to change it, or use Add city to compare up to five. Each row shows the local date and how far ahead or behind it is.
• Click any hour on the working-hours chart to jump to it. Back to now returns the clocks to live time.
• Every city comes from your browser's time zone database, so daylight saving is applied for you. If a city is missing, pick another in the same zone: only the zone matters.

• It checks each of the next 24 hours and keeps the ones where every city is between 09:00 and 18:00 local time.
• The best slot is the one that keeps everyone closest to midday. Other shared hours appear as alternatives you can select.
• If nothing overlaps, it shows the closest option and marks which cities fall outside working hours.
• Copy the summary into an email, or add the slot to your calendar as a one-hour event.

Take 16:00 UTC. To get a city's local time, add its UTC offset. London is UTC+0 in winter, so it is 16:00. New York is UTC-5, so it is 11:00. Tokyo is UTC+9, so it is 01:00, which is already the next day.

In July London moves to UTC+1 and New York to UTC-4. The table shows both seasons, calculated from the time zone database.

• Flight and train times are always in local time at each airport or station, so a 22:00 departure that lands at 08:00 may be shorter or longer than it looks.
• Daylight saving starts and ends on different dates in different regions. For a few weeks each year the gap between the US and Europe is an hour different from usual.
• The southern hemisphere shifts in the opposite season, so Australia and New Zealand change when Europe and North America do not.
• Some zones are not whole hours from UTC. India is UTC+5:30 and Nepal is UTC+5:45. Do not round when you schedule.
• China uses a single time zone for the whole country, even though it spans several.
• Plan the first day after a long flight lightly. A common rule of thumb is about one day of adjustment per time zone crossed.

• Using abbreviations. IST can mean India, Ireland or Israel, and CST can mean the central US, China or Cuba. Name a city or a UTC offset instead.
• Leaving out the date. A meeting at 07:00 on Monday in Sydney is still Sunday evening in London.
• Forgetting daylight saving. Two cities can be 4 hours apart in one week and 5 hours apart the next.
• Rounding half-hour zones. 14:00 in India is 08:30 UTC, not 09:00.

• UTC offset: how far a zone is from UTC, such as UTC+5:30. Subtract it to get UTC, then add the target city's offset.
• Daylight saving time: a seasonal one-hour shift that changes a city's UTC offset for part of the year.
• Date rollover: when a city is ahead or behind enough that its calendar date differs from yours. Rows show Next day or Previous day.
• Time difference: the gap between two cities at one moment. It can change during the year, which is why this tool calculates it each time.