Travel time-zone tool

Jet lag time-zone calculator

Compare departure and destination time zones, see the clock shift and get a simple planning estimate for how large the adjustment may feel.

Choose departure and destination.

What this calculator can and cannot tell you

Jet lag is a circadian-rhythm effect, not just a clock calculation. The tool can measure the time-zone shift accurately for your selected date, but individual adjustment varies with sleep timing, light exposure, travel direction and personal factors. The result is therefore a travel-planning guide, not medical advice.