Time Zone Converter & Meeting Planner

How this time zone converter works

Every time shown on this page is calculated by your own browser from the IANA time zone database, the same reference data used by operating systems, airlines and programming languages worldwide. That means daylight saving changes are handled automatically: if London moves to BST or New York enters EDT, the converter reflects it on the correct date without you doing anything.

Your city list is saved on your device only, so the next time you open this page your zones are already there. Nothing is sent to a server.

Using the meeting planner

The grid shows the next 24 hours for every city in your list, one row per city. Green cells are core business hours (9:00 to 18:00 local), amber cells are early morning or evening hours that many people will still accept (7:00 to 9:00 and 18:00 to 21:00), and grey cells are night hours you should avoid. Scan vertically for a column where every row is green or amber: that column is your meeting slot.

Common conversions people look up

India runs on a single zone, IST (UTC+5:30), with no daylight saving. New York is 10 hours 30 minutes behind IST during US winter (EST) and 9 hours 30 minutes behind during US summer (EDT), and people mix the two up constantly, which is exactly why a converter beats memory. London is 5.5 hours behind IST in winter and 4.5 in summer. Dubai is a fixed 1.5 hours behind IST year-round. Singapore and Hong Kong are 2.5 hours ahead of IST. When in doubt, add the cities above and read it off live.

Why half-hour zones exist

India (UTC+5:30), Iran (UTC+3:30) and parts of Australia (UTC+9:30) chose offsets that split the difference across their geography. Nepal goes further at UTC+5:45. The converter supports every official zone, including these unusual ones.

Worked example: a call across three continents

Your team sits in Coimbatore, London and San Francisco. Add all three cities and scan the planner: 18:30 IST is 14:00 in London (green) and 06:00 in San Francisco (red), while 20:30 IST is 16:00 London and 08:00 San Francisco, the first column where nobody is asleep. That single glance replaces the usual email thread of guessed conversions, and dragging the slider to the agreed hour lets you paste exact local times into the invite: 20:30 IST / 16:00 BST / 08:00 PDT.

UTC: the anchor everything hangs on

Every zone is defined as an offset from Coordinated Universal Time. Servers, aviation and financial markets log events in UTC precisely because it never shifts for daylight saving. When scheduling across zones in writing, quoting the UTC time alongside local times ("15:00 UTC, that is 20:30 IST") removes the last ambiguity, especially in the weeks around March and November when US and European offsets change on different dates.