this zone, though legally they calculate time specifically as an offset of four hours from GreenwichMeanTime (GMT–4) rather than from UTC. Small portions
uses GreenwichMeanTime (also known as Western European Time or UTC) and British Summer Time (UTC+01:00) (also known as Western European Summer Time). Until
daylight saving time. The clock time in this zone is based on the mean solar time of the meridian 52 degrees and 30 arcminutes west of the Greenwich Observatory
this they were based upon the mean solar time at several meridians 15° apart west of Greenwich (GMT). Only the full-time zone names listed below are official;