The overlap sweet spot for US–Europe meetings
New York is UTC-5 (EST) or UTC-4 (EDT). London is UTC+0 (GMT) or UTC+1 (BST). The difference is 5 hours in winter and 4 hours in spring/summer. The overlap window for standard business hours (9am–6pm) is approximately 2pm–5pm New York time (7pm–10pm London) in winter, or 3pm–6pm NYC (8pm–11pm London) — uncomfortable for London but workable. Many teams settle on a 3pm–4pm EST weekly call as a compromise.
The US West Coast–Asia Pacific impossibility
San Francisco (UTC-8) and Tokyo (UTC+9) are 17 hours apart. When it is 9am Monday in San Francisco, it is 2am Tuesday in Tokyo. There is no overlap between standard business hours in both locations — the only viable synchronous option is very early San Francisco morning (6–7am) which is 11pm–midnight in Tokyo, or vice versa. Most SF–Tokyo teams operate asynchronously with one weekly overlap meeting at an uncomfortable time for one party.
Always include the date when sharing times across time zones
Time zone differences can cross midnight, meaning the same moment is a different calendar date in different locations. A meeting at 11pm Thursday in New York is 3am Friday in London and 8am Friday in Dubai. When scheduling, always share the date alongside the time to avoid the "but I thought it was on Thursday" confusion.
Watch for DST transition weeks
When the US and Europe change clocks at different times (the US changes in March, Europe changes about 3 weeks later), the time difference between US and European cities temporarily shifts by 1 hour. A standing weekly call at a fixed time in each location will be at the wrong relative time during transition weeks. Use the converter with specific dates during transition weeks to verify.
The "follow the sun" model for support teams
Global customer support teams often use a "follow the sun" rotation: team A covers their business hours, then hands off to team B in a later time zone, which hands off to team C. Three teams covering Sydney, London, and San Francisco can provide 24-hour coverage with each team working only normal business hours. The converter helps plan handoff times so coverage is seamless.