GMT/IST
Greenwich Mean Time
GMT +0
12am
3am
6am
9am
12pm
3pm
6pm
9pm
IST is not used on this date
This converter uses GMT (GMT +0), the offset Dublin uses on this date. Open the GMT converter.
CET/CEST
Central European Time
GMT +1
12am
3am
6am
9am
12pm
3pm
6pm
9pm
CEST is not used on this date
This converter uses CET (GMT +1), the offset Berlin uses on this date. Open the CET converter.

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

Time Difference

Greenwich Mean Time is 1 hour behind Central European Time
12:00 pm12:00 in GMT is 1:00 pm13:00 in CET

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

12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
1:00 pm13:00 Central European Time (CET). Offset UTC +1:00 hour

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

GMTCET
12am (midnight)1am
1am2am
2am3am
3am4am
4am5am
5am6am
6am7am
7am8am
8am9am
9am10am
10am11am
11am12pm (noon)
12pm (noon)1pm
1pm2pm
2pm3pm
3pm4pm
4pm5pm
5pm6pm
6pm7pm
7pm8pm
8pm9pm
9pm10pm
10pm11pm
11pm12am (midnight)
00:0001:00
01:0002:00
02:0003:00
03:0004:00
04:0005:00
05:0006:00
06:0007:00
07:0008:00
08:0009:00
09:0010:00
10:0011:00
11:0012:00
12:0013:00
13:0014:00
14:0015:00
15:0016:00
16:0017:00
17:0018:00
18:0019:00
19:0020:00
20:0021:00
21:0022:00
22:0023:00
23:0000:00

Irish Standard Time

Offset: IST is 1 hour ahead Greenwich Mean Time (GMT) and is used in Europe

Countries using this time zone: Ireland

Principal Cities: The largest city in the IST time zone is Dublin in Ireland, with about 1.024 million people. Other major cities in this time zone include Cork, Dun Laoghaire, Luimneach, Gaillimh.

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.

IST Time Zone Geo Map
IST timezone map

IST 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 IST
  • A - short form of 'Alpha'
IANA/Olson: Reflects IST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Eire
  • Europe/Dublin
IST Abbreviation: Several time zones share IST abbreviation and it could refer to these time zones
  • India Standard Time - UTC +5:30
  • Irish Standard Time - UTC +1
  • Israel Standard Time - UTC +2
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

Central European Summer Time

Offset: CEST is 2 hours ahead Greenwich Mean Time (GMT) and is used in Europe

Countries using this time zone: Andorra, Albania, Austria, Bosnia & Herzegovina, Belgium, Switzerland, Czech Republic, Germany, Denmark, Spain, France, Gibraltar, Croatia, Hungary, Italy, Liechtenstein, Luxembourg, Monaco, Montenegro, North Macedonia, Malta, Netherlands, Norway, Poland, Serbia, Sweden, Slovenia, Svalbard & Jan Mayen, Slovakia, San Marino, Vatican City

Principal Cities: The largest city in the CEST time zone is Berlin in Germany, with about 3.426 million people. Other major cities in this time zone include Madrid, Rome, Paris, Budapest.

German: MESZ - Mitteleuropäische Sommerzeit

CEST Time Zone Geo Map
CEST timezone map

Daylight Saving: Central European Summer Time (CEST) is a daylight saving/summer time zone, but some places set clocks back one hour during winter and observe Central European Time (CET).

Daylight saving time clock moves forward for one hour from 3am to 4amEnd: Central European Summer Time (CEST) ended on Sunday, October 26, 2025 at 3:00 am local time and clocks were set one hour back to Sunday, October 26, 2025, 2:00 am local standard time instead. Daylight saving ends annually on the last Sunday of October

Daylight saving time clock moves back for one hour from 2am to 1amStart: Central European Summer Time (CEST) starts on Sunday, March 29, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 29, 2026, 3:00 am. Daylight saving starts annually on the last Sunday of March

CEST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +02 - basic short
  • +0200 - basic
  • +02:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0200 - sign character (+) followed by a four digit time providing hours (02) and minutes (00) of the offset. Indicates an offset of two hours to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Bravo - Military abbreviation for CEST
  • B - short form of 'Bravo'
IANA/Olson: Reflects CEST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Africa/Ceuta
  • Arctic/Longyearbyen
  • Atlantic/Jan_Mayen
  • CET
  • Europe/Amsterdam
  • Europe/Andorra
  • Europe/Belgrade
  • Europe/Berlin
  • Europe/Bratislava
  • Europe/Brussels
  • Europe/Budapest
  • Europe/Busingen
  • Europe/Copenhagen
  • Europe/Gibraltar
  • Europe/Ljubljana
  • Europe/Luxembourg
  • Europe/Madrid
  • Europe/Malta
  • Europe/Monaco
  • Europe/Oslo
  • Europe/Paris
  • Europe/Podgorica
  • Europe/Prague
  • Europe/Rome
  • Europe/San_Marino
  • Europe/Sarajevo
  • Europe/Skopje
  • Europe/Stockholm
  • Europe/Tirane
  • Europe/Vaduz
  • Europe/Vatican
  • Europe/Vienna
  • Europe/Warsaw
  • Europe/Zagreb
  • Europe/Zurich
  • MET
  • Poland
Time zones with the GMT +2 offset:
  • CEST - Central European Summer Time
  • EET - Eastern European Time
  • MESZ - Mitteleuropäische Sommerzeit
  • B - Bravo Time Zone
  • CAT - Central Africa Time
  • IST - Israel Standard Time
  • SAST - South Africa Standard Time
  • WAST - West Africa Summer Time