Timezone Converter

Pick a source time and zone, get the equivalent in every zone you care about — simultaneously, side by side. Designed for distributed teams scheduling meetings: pick “2 PM in San Francisco” and see it in London, Bangalore, and Sydney without juggling multiple browser tabs. Uses the browser’s built-in Intl APIs, so DST transitions and historical changes are handled correctly without manual offset math.

How to use the Timezone Converter

Set the source time and zone (default is your local zone now). Add target zones from the dropdown — each shows the equivalent local time, the offset from the source, and the day-of-week (so you spot when “Friday afternoon” in California is already Saturday in Sydney).

Click Workday overlap heatmap to see a 24-hour grid showing which hours are workday-friendly (9-17 local) for every added zone simultaneously — useful for finding meeting times when nobody has to be awake at 3 AM.

About Timezone Converter

Timezone math is one of the few places where every developer has been bitten at least once. Naive UTC offset arithmetic breaks at DST transitions. Hard-coded offsets become wrong when a country changes its DST rules (Turkey did this in 2016; Russia, Egypt, and several US territories have done it more recently). The only reliable approach is to defer to the IANA timezone database, which every modern browser ships via the Intl.DateTimeFormat API. This converter uses exactly that: pick an IANA zone like America/Los_Angeles or Europe/London, and the conversion respects historical and future DST rules without manual fiddling.

The overlap heatmap solves a separate problem: even when you know what time it is everywhere, finding a meeting slot that works for everyone’s working hours is mentally taxing. The heatmap is a quick visual: green where everyone’s in 9-17, yellow where someone is in extended hours, red where someone is asleep.

Common use cases

  • Distributed-team meeting scheduling — find an hour that works for SF, London, and Bangalore.
  • Customer support handoff — confirm when the next region’s on-call comes online.
  • Release / deploy windows — pick a UTC slot that’s after-hours for primary region but during business hours for the on-call.
  • Travel planning — see what time you’ll arrive in local time.

Frequently asked questions

Why no UTC dropdown?
UTC is always offset 00:00 with no DST, so it's already in the list as itself. Many local zones internally evaluate to UTC at certain times of year (e.g., London in winter is UTC).

How accurate is the DST handling?
As accurate as your browser's IANA database, which is updated with every browser release. For historical dates more than a few decades back, accuracy is lower (DST rules pre-1970 are spotty in IANA itself).

Can I share a link to a specific time?
Not in this version \xE2\x80\x94 use the timezone abbreviation in the URL when sharing (e.g. "2 PM PT" rather than a generated link).