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Airport time difference calculator

Pick two airports and a date to see how far apart their clocks are that day — daylight saving included — with every date in the year the gap changes, and the hours side by side.

JFK · New York

UTC−05:00

America/New_York · EST · standard time

local at the moment compared

LHR · London

UTC+00:00

Europe/London · GMT · standard time

local at the moment compared

Flight distance and time, JFK → LHR →Jet lag plan for this trip →

+5hLHR vs JFK

London is 5 hours ahead of New York.

Noon in New York is 17:00 in London.

  • New York is on standard time (EST, UTC−05:00) on 15 Jan. Clocks go forward on 14 Mar.
  • London is on standard time (GMT, UTC+00:00) on 15 Jan. Clocks go forward on 28 Mar.
  • From 19:00 in New York, it's already the next day in London.

The gap isn't fixed: it's 5 hours for most of the year and 4 hours for 21 days, because New York and London change their clocks on different dates. See the year

The gap through 2027

5 stretches, 2 different gaps

London relative to New York, compared at noon in New York. Pick a stretch to jump to it.

Hour by hour

Every hour of 15 Jan in New York, side by side

Local time in London for each hour in New York on 15 Jan 2027
JFK000102030405060708091011121314151617181920212223
LHR0506070809101112131415161718192021222300+1d01+1d02+1d03+1d04+1d

Shaded: night (22:00–07:00). Amber: a different date in London — +1d the next day, −1d the previous one.

Flying New York to London? Log it in Orbit — the distance, the hours and the time zones crossed, on a globe you keep.

Add JFK → LHR to Orbit
How it works

Real time zones, on the day you fly

Each airport's time zone is looked up from its coordinates against the timezone-boundary-builder map, which gives the IANA name — Europe/London, America/New_York — rather than an abbreviation like CST, which means three different places.

The offset on your date comes from the IANA time zone database built into your browser, through its Intl API. So every daylight-saving rule is the one your own clock follows, and the calculation never leaves the page.

The two clocks are compared at noon at the first airport. Clocks change in the early hours, so on a change day noon gives the gap for most of the day, and the calculator says what it was before.

Planning the flight itself? Get the flight distance and time, find other airports nearby, draw the trip with the route map generator or check its carbon footprint. Crossing several time zones? Plan the adjustment with the jet lag calculator.

Time difference

Questions about time zones and flights

Because the answer depends on it. London and New York are 5 hours apart for most of the year, but 4 hours for a few weeks in March and late October, when the US has changed its clocks and the UK hasn't yet. The calculator works out each airport's offset on the date you choose and lists every change in that year.

Every time zone you’ve crossed, logged.

Orbit keeps each flight — the airports, the distance, the hours, the countries — on a globe you can spin. Offline, free to start.

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