Nowadays, Greenwich Mean Time, abbreviated as GMT, is a time zone designation rather than a time standard. Time difference between time zones can be expressed by the GMT or UTC offset. In the UTC standard, there is a commitment to keep within 0.9 seconds of GMT, so that every few years a leap second is applied to UTC. In the age of the internet, these small clock calibrations are conveniently distributed via NTP.
UTC/GMT+1 is 1 hour ahead of Greenwich Mean Time (GMT).
UK, Ireland and Portugal are on GMT/UTC+1 only during the Daylight Saving Time (DST) period. The +1 offset applies to the Western European Time Zone (WET), under different designations for each country
Enter your location or any place of your choice for more comparisons.
The following countries or regions use the offset +1 either in Standard time or Daylight Saving Time as indicated.