World Time Meeting Planner
Find the best meeting time across multiple time zones for international calls. Enter values for instant results with step-by-step formulas.
Reviewed by Abdullah, Technical Content Specialist
Formula
Local Time = Base Time - Base UTC Offset + Target UTC Offset
Convert the meeting time to UTC by subtracting the base time zone offset, then add each participant time zone offset to find their local time. Business hours are defined as 9:00-17:00, and extended hours as 7:00-21:00. The planner finds all hours where every participant falls within these windows.
Worked Examples
Example 1: US-Europe-India Meeting
Problem:Find a meeting time that works for New York (UTC-5), London (UTC+0), and Mumbai (UTC+5:30).
Solution:Spread: 10.5 hours. Business hours overlap:\nNew York 9 AM = London 2 PM = Mumbai 7:30 PM (extended for India)\nNew York 8 AM = London 1 PM = Mumbai 6:30 PM (extended for India)\nBest slot: 9:00 AM Eastern = 2:00 PM London = 7:30 PM Mumbai\nThis keeps everyone within 7 AM - 9 PM range.
Result:Best time: 9:00 AM EST / 2:00 PM GMT / 7:30 PM IST
Example 2: US West Coast to Asia
Problem:Schedule a call between San Francisco (UTC-8) and Beijing (UTC+8).
Solution:Spread: 16 hours. No normal business hours overlap exists.\nExtended options:\nSF 6:00 PM = Beijing 10:00 AM (next day) - good for Beijing\nSF 7:00 AM = Beijing 11:00 PM - late for Beijing\nBest compromise: SF 5:00-6:00 PM = Beijing 9:00-10:00 AM (+1 day)
Result:Best time: 5:00 PM PST / 9:00 AM CST (+1 day)
Frequently Asked Questions
How do I find the best meeting time across multiple time zones?
To find the best meeting time across multiple time zones, you need to identify the overlapping business hours for all participants. Standard business hours are typically 9 AM to 5 PM in each time zone. The overlapping window shrinks as the time zone spread increases. For zones within 8 hours of each other, there is usually at least a 1-hour overlap during normal business hours. World Time Meeting Planner automatically finds all hours where every participant would be within business hours (9-17) and also identifies extended hours (7-21) for when no perfect overlap exists. The key is to find the time that causes the least inconvenience to the maximum number of participants.
What is UTC and how does it relate to time zones?
UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks and time. It is essentially the same as Greenwich Mean Time (GMT) but defined more precisely using atomic clocks. All time zones are expressed as positive or negative offsets from UTC. For example, US Eastern Time is UTC-5 (five hours behind UTC), while Japan Standard Time is UTC+9 (nine hours ahead). UTC does not observe daylight saving time, which is why some time zones shift their offset seasonally. When planning international meetings, converting all times to UTC first and then back to local times ensures accuracy. UTC replaced GMT as the international standard in 1960.
How does daylight saving time affect meeting planning?
Daylight saving time (DST) significantly complicates international meeting planning because different countries change their clocks on different dates, and some do not observe DST at all. The United States springs forward on the second Sunday in March and falls back on the first Sunday in November. Europe changes on the last Sundays in March and October. Australia changes in October and April (opposite seasons in the Southern Hemisphere). During the transition periods when some regions have changed and others have not, the offset between two cities can temporarily shift by one or two hours from its usual value. This means a meeting time that works perfectly in January might not work in March. Always verify current UTC offsets when scheduling across DST boundaries.
How many time zones exist in the world?
The world has 38 distinct time zones currently in use, ranging from UTC-12 to UTC+14. While you might expect only 24 time zones (one per hour), the existence of half-hour and quarter-hour offsets, plus the International Date Line adjustments, creates more than 24 distinct zones. Some countries span multiple time zones: Russia leads with 11, the United States has 6 (including Alaska and Hawaii), Canada has 6, and Australia has 3 standard zones. China, despite spanning five geographical time zones, uses a single zone (UTC+8) nationwide for political unity. France technically has the most time zones of any country (12) when including its overseas territories scattered across the globe.
References
Reviewed by Abdullah, Technical Content Specialist · Editorial policy