Offsets

Time Difference Calculator

Compare two zones

Offset difference = destination UTC offset − source UTC offset, both taken at the same instant. New York and London do not keep a single difference all year because their transitions are not always on the same date.

Reference date Reference time

First time zone

Second time zone

First zone UTC offset: —

Second zone UTC offset: —

Time difference: —

Which location is ahead: —

Why the difference moves

Compare New York and London in January and again in mid-March. US and UK transition dates do not always coincide, so the hour gap can change even if both regions “use daylight saving” in the same year. Walk through the arithmetic in how to calculate time difference.