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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.

LHR · London

UTC+00:00

Europe/London · GMT · standard time

local at the moment compared

JFK · New York

UTC−05:00

America/New_York · EST · standard time

local at the moment compared

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

−5hJFK vs LHR

New York is 5 hours behind London.

Noon in London is 07:00 in New York.

  • London is on standard time (GMT, UTC+00:00) on 15 Jan. Clocks go forward on 29 Mar.
  • New York is on standard time (EST, UTC−05:00) on 15 Jan. Clocks go forward on 8 Mar.
  • Until 05:00 in London, it's still the previous day in New York.

The gap isn't fixed: it's 5 hours for most of the year and 4 hours for 28 days, because London and New York change their clocks on different dates. See the year

The gap through 2026

5 stretches, 2 different gaps

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

Hour by hour

Every hour of 15 Jan in London, side by side

Local time in New York for each hour in London on 15 Jan 2026
LHR000102030405060708091011121314151617181920212223
JFK19−1d20−1d21−1d22−1d23−1d00010203040506070809101112131415161718

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

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

Add LHR → JFK 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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