Date-aware offsets
New York to London is not always the same number of hours because daylight-saving transitions start on different dates.
Time zone tool
Time Difference Calculator
Compare a selected date and time between cities or IANA time zones. The result uses the selected date, so daylight-saving changes are handled more accurately than a fixed UTC offset table.
City or IANA input
Use city names for common cases, or precise IDs such as Asia/Tokyo, Europe/Berlin, America/Los_Angeles, and Australia/Sydney.
Planning context
The nearby conversion table helps compare adjacent hours for calls, travel handoffs, livestreams, launches, and deadlines.
Common time difference examples
| Route | Why the date matters | Useful for |
|---|---|---|
| New York to London | US and UK daylight-saving switches do not always happen on the same week. | Finance calls, webinars, launch planning |
| Los Angeles to Tokyo | Tokyo does not use daylight saving, while California does. | Product releases, support handoffs |
| London to Sydney | Both regions can shift clocks, but on different seasonal cycles. | Remote teams, travel calls |
Popular city-to-city comparisons
Open a prefilled route page, then adjust the date to account for daylight-saving changes.
How to compare two places accurately
Choose a real date before trusting the offset between two cities. Many time difference mistakes happen during the few weeks when one country has changed clocks and another has not. A date-aware comparison is especially important for flight calls, market opens, release freezes, and recurring meetings.
When the exact city is known, use a city or IANA time zone instead of a short abbreviation. Labels such as CST, IST, and BST can mean different places, while identifiers such as America/Chicago or Europe/London are designed for software scheduling.
Pick the right comparison view
A time difference calculator is best when the question is simple: how many hours apart are two places on a specific date? If you already have one source event and need several audience times, use the time zone converter. If you need a live current-time board for operations or support, use the world clock.
For scheduling, compare the offset first, then check whether the local hour is usable for the people involved. The working hours overlap, business meeting planner, and international call planner can turn the offset into a practical meeting window.
Checks for recurring meetings and deadlines
For a recurring meeting, test at least one date near the next daylight-saving change and one date several months later. A pair of cities can be five hours apart in one month and four or six hours apart in another. If the event crosses midnight, write the weekday and date beside the converted time so the destination team does not read the wrong day.
The calculations rely on browser time zone data and IANA-style identifiers where available. Review the time zone data notes for sourcing details, the editorial policy for review standards, or send feedback if a city label or offset example needs correction.
Convert one event time into multiple cities.
Flight Time ZonesCalculate flight arrival dates across time zones.
Meeting PlannerFind overlap windows for global teams.
Remote SchedulerAnalyze working-hour overlap across locations.
Travel Time ZonesPlan jet lag and arrival-time adjustments.
World ClockTrack live local times for your main cities.
Working HoursTurn offsets into practical collaboration windows.
Call PlannerPlan calls across customer and team locations.
Time Zone DataRead calculation and data source notes.
Editorial PolicyReview how time guidance is maintained.
FeedbackReport a city, offset, or wording issue.
Privacy PolicyReview advertising, cookies, analytics, and local storage.
Review notes before using the result
For contractual deadlines, payroll cutoffs, travel plans, public events, or customer commitments, treat the calculator output as planning guidance and confirm the final time with the responsible platform or organization. The time zone data notes, editorial policy, feedback page, and privacy policy explain how calculations, corrections, advertising, cookies, analytics, and local storage are handled.