A
Alpha Time Zone
GMT +1
12am
3am
6am
9am
12pm
3pm
6pm
9pm
GMT
Greenwich Mean Time
GMT +0
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

A is 1 hour ahead of GMT. A uses GMT +1, and GMT uses GMT +0 for this comparison.

For example, 1:00 pm A is 12:00 pm GMT. Use the converter above to adjust the date or time and create a shareable meeting link.

Best meeting overlap: 10am-5pm A, which is 9am-4pm GMT.

Compare A time with GMT time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

Alpha Time Zone is 1 hour ahead of Greenwich Mean Time
1:00 pm13:00 in A is 12:00 pm12:00 in GMT

A to GMT call time
Best time for a conference call or a meeting is between 10am-5pm in A which corresponds to 9am-4pm in GMT

1:00 pm13:00 Alpha Time Zone (A). Offset UTC +1:00 hour
12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours

1:00 pm13:00 A / 12:00 pm12:00 GMT

AGMT
12am (midnight)11pm
1am12am (midnight)
2am1am
3am2am
4am3am
5am4am
6am5am
7am6am
8am7am
9am8am
10am9am
11am10am
12pm (noon)11am
1pm12pm (noon)
2pm1pm
3pm2pm
4pm3pm
5pm4pm
6pm5pm
7pm6pm
8pm7pm
9pm8pm
10pm9pm
11pm10pm
00:0023:00
01:0000:00
02:0001:00
03:0002:00
04:0003:00
05:0004:00
06:0005:00
07:0006:00
08:0007:00
09:0008:00
10:0009:00
11:0010:00
12:0011:00
13:0012:00
14:0013:00
15:0014:00
16:0015:00
17:0016:00
18:0017:00
19:0018:00
20:0019:00
21:0020:00
22:0021:00
23:0022:00

Alpha Time Zone

Offset: A is 1 hour ahead Greenwich Mean Time (GMT) and is used in Military

Daylight Saving: Clocks in Alpha Time Zone (A) do not change for daylight saving time, so A stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

A representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +01 - basic short
  • +0100 - basic
  • +01:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0100 - sign character (+) followed by a four digit time providing hours (01) and minutes (00) of the offset. Indicates an offset of one hour to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Alpha - Military abbreviation for A
  • A - short form of 'Alpha'
Time zones with the GMT +1 offset:
  • BST - British Summer Time
  • CET - Central European Time
  • IST - Irish Standard Time
  • WEST - Western European Summer Time
  • A - Alpha Time Zone
  • CET - Central European Time
  • MEZ - Mitteleuropäische Zeit
  • WAT - West Africa Time
  • WST - Western Sahara Summer Time
  • BMT - Biel Mean Time

Greenwich Mean Time

Offset: GMT is 0 hours ahead Greenwich Mean Time (GMT) and is used in Europe

Countries using this time zone: Burkina Faso, Côte d'Ivoire, Britain (UK), Guernsey, Ghana, Greenland, Gambia, Guinea, Guinea-Bissau, Ireland, Isle of Man, Iceland, Jersey, Liberia, Mali, Mauritania, St Helena, Sierra Leone, Senegal, Sao Tome & Principe, Togo

Principal Cities: The largest city in the GMT time zone is London in United Kingdom, with about 7.557 million people. Other major cities in this time zone include Abidjan, Dakar, Grand Dakar, Accra.

Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use for the most parts it is the same. In military GMT is known as Zulu time.Greenwich Mean Time was the same as Universal Time (UT), until the introduction of UTC in 1972 a standard astronomical concept used in many technical fields.

GMT Time Zone Geo Map
GMT timezone map

GMT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
  • +00 - basic short
  • +0000 - basic
  • +00:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Zulu - Military abbreviation for GMT
  • Z - short form of 'Zulu'
IANA/Olson: Reflects GMT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Africa/Abidjan
  • Africa/Accra
  • Africa/Bamako
  • Africa/Banjul
  • Africa/Bissau
  • Africa/Conakry
  • Africa/Dakar
  • Africa/Freetown
  • Africa/Lome
  • Africa/Monrovia
  • Africa/Nouakchott
  • Africa/Ouagadougou
  • Africa/Sao_Tome
  • Africa/Timbuktu
  • America/Danmarkshavn
  • Atlantic/Reykjavik
  • Atlantic/St_Helena
  • Eire
  • Etc/GMT
  • Etc/GMT+0
  • Etc/GMT-0
  • Etc/GMT0
  • Etc/Greenwich
  • Europe/Belfast
  • Europe/Dublin
  • Europe/Guernsey
  • Europe/Isle_of_Man
  • Europe/Jersey
  • Europe/London
  • GB
  • GB-Eire
  • GMT
  • GMT+0
  • GMT-0
  • GMT0
  • Greenwich
  • Iceland
Time zones with the GMT +0 offset:
  • EGST - Eastern Greenland Summer Time
  • GMT - Greenwich Mean Time
  • WET - Western European Time
  • AZOST - Azores Summer Time
  • UTC - Universal Time Coordinated
  • WT - Western Sahara Standard Time
  • Z - Zulu Time Zone