IST
Irish Standard Time
GMT +1
AST
Azores Summer Time
GMT +0

Time Difference

Irish Standard Time is 1 hour ahead of Azores Summer Time
12:30 am00:30 in IST is 11:30 pm23:30 in AST

IST to AST call time
Best time for a conference call or a meeting is between 9am-6pm in IST which corresponds to 8am-5pm in AST

12:30 am00:30 Irish Standard Time (IST). Offset UTC +1:00 hour
11:30 pm23:30 Azores Summer Time (AST). Offset UTC 0:00 hours

12:30 am00:30 IST / 11:30 pm23:30 AST

IST AST
12am (midnight) 11pm
1am 12am (midnight)
2am 1am
3am 2am
4am 3am
5am 4am
6am 5am
7am 6am
8am 7am
9am 8am
10am 9am
11am 10am
12pm (noon) 11am
1pm 12pm (noon)
2pm 1pm
3pm 2pm
4pm 3pm
5pm 4pm
6pm 5pm
7pm 6pm
8pm 7pm
9pm 8pm
10pm 9pm
11pm 10pm
0:00 23:00
1:00 0:00
2:00 1:00
3:00 2:00
4:00 3:00
5:00 4:00
6:00 5:00
7:00 6:00
8:00 7:00
9:00 8:00
10:00 9:00
11:00 10:00
12:00 11:00
13:00 12:00
14:00 13:00
15:00 14:00
16:00 15:00
17:00 16:00
18:00 17:00
19:00 18:00
20:00 19:00
21:00 20:00
22:00 21:00
23:00 22:00

Irish Standard Time

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

Countries: It is used in following countries: Ireland

Principal Cities: The largest city in the IST timezone is Dublin from Ireland with population about 1.024 million people. Other major cities in the area are Cork, Dun Laoghaire, Luimneach, Gaillimh

IST Time Zone Geo Map
IST timezone map

Daylight Saving: This is a standard timezone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Greenwich Mean Time (GMT).

Start: Irish Standard Time (IST) started on Sunday, March 31, 2024 at 3:00 am local time and clocks were set one hour back to Sunday, March 31, 2024, 2:00 am. Standard time starts annually the on last Sunday of March.

End: Irish Standard Time (IST) ends on Sunday, October 27, 2024 at 2:00 am local time and clocks are set one hour forward to Sunday, October 27, 2024, 3:00 am local daylight time instead. Standard time starts annually the on last Sunday of October.

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 one hour and zero minutes time differences 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
  • Iran Standard Time - UTC +3:30
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

Azores Summer Time

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

AST 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 zero hour and zero minutes time differences of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Zulu - Military abbreviation for AST
  • Z - short form of 'Zulu'
AST Abbreviation: Several time zones share AST abbreviation and it could refer to these time zones
  • Atlantic Standard Time - UTC -4
  • Arabia Standard Time - UTC +3
  • Arabian Standard Time - UTC +3
  • Argentina Standard Time - UTC -3
  • Apia Standard Time - UTC +13
  • Azores Summer Time - UTC +0
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