<P> Earth is split up into a number of time zones . Most time zones are exactly one hour apart , and by convention compute their local time as an offset from GMT . For example , time zones at sea are based on GMT . In many locations ( but not at sea ) these offsets vary twice yearly due to daylight saving time transitions . </P>
<P> Earth is split up into a number of time zones . Most time zones are exactly one hour apart , and by convention compute their local time as an offset from GMT . For example , time zones at sea are based on GMT . In many locations ( but not at sea ) these offsets vary twice yearly due to daylight saving time transitions . </P>
which method of measuring time using time zones
which method of measuring time using time zones
GMT
GMT