How to Calculate Time Zone Differences for Meetings
UTC, time zones, daylight saving and practical ways to plan meetings across countries.
The most common mistake when arranging meetings across countries is getting the time difference wrong. Once you understand the logic it is easy.
What is UTC?
UTC is the reference for world time. Turkey is UTC+3, Azerbaijan UTC+4, London UTC+0 in winter and UTC+1 in summer, New York UTC−5 in winter and UTC−4 in summer.
Finding the difference
Subtract the two UTC offsets. Istanbul (UTC+3) and New York in winter (UTC−5) are 3 − (−5) = 8 hours apart; in summer New York is UTC−4 so the gap is 7 hours.
The daylight-saving trap
Europe and the US move clocks forward between March and October/November, but on different dates. For a few weeks each year the gap is an hour different. Turkey stays on one time all year, so the gap changes. A converter that uses the actual date is safest.
Meeting tips
- Put both time zones in the invite.
- Choose the overlap of working hours.
- State the date when a time crosses midnight.
Use the Time Zone Converter for a quick conversion between two cities, or World Clock to see several cities side by side.