World Clock for Travelers

How to use the world clock on a trip

Add your home city first, then every city on your itinerary — including layover airports. The clock wall updates live, so a single glance tells you whether it is a reasonable hour to call the hotel in Kyoto, whether your bank's fraud line in New York is staffed right now, and how many hours of daylight are left at your destination while you are still in the air.

The three time-zone mistakes travelers actually make

Booking on the wrong calendar day. Overnight flights arrive on the date shown in the destination's zone, not yours. A 23:40 departure landing "the same night" often lands the following afternoon local time, and hotels charge for the night you did not sleep in.

Ignoring daylight saving offsets. The gap between New York and London is five hours most of the year but four hours for two short windows each spring and fall, because the two regions switch on different dates. Most of the southern hemisphere shifts in the opposite direction. The clock here reads live zone data, so it already accounts for whichever rule is in force today.

Half-hour and quarter-hour zones. India (UTC+5:30), Iran (UTC+3:30), parts of Australia (UTC+9:30), Nepal (UTC+5:45), and the Chatham Islands (UTC+12:45) do not sit on whole-hour offsets. Mental arithmetic quietly fails for these; reading the actual clock does not.

Jet lag planning

A practical rule of thumb is roughly one day of adjustment per time zone crossed, with eastward travel harder than westward. Two or three days before a long eastward flight, shift your bedtime earlier by an hour a night and use the clock wall to sanity-check what "morning light" means at the destination — getting outside during the destination's morning is the single strongest cue for resetting your body clock. Pair this with our long-haul flight health guide for the in-flight side of the same problem.

Frequently Asked Questions