IST meaning in Regional ?

Answer: What is Irish Summer Time mean?

Ireland uses Irish Standard Time (IST, UTC+01:00; Irish: Am Caighdeánach Éireannach) in the summer months and Greenwich Mean Time (UTC+00:00; Meán-Am Greenwich) in the winter period. (Roughly half of the state is in the 7.5°W to 22.5°W sector, half is in the same sector as Greenwich: 7.5°E to 7.5°W).

In Ireland, the Standard Time Act 1968 legally established that the time for general purposes in the State (to be known as standard time) shall be one hour in advance of Greenwich mean time throughout the year. This act was amended by the Standard Time (Amendment) Act 1971, which legally established Greenwich Mean Time as a winter time period. Ireland therefore operates one hour behind standard time during the winter period, and reverts to standard time in the summer months. This is defined in contrast to the other states in the European Union, which operate one hour ahead of standard time during the summer period, but produces the same end result.

The instant of transition to and from daylight saving time is synchronised across Europe. In Ireland, winter time begins at 02:00 IST on the last Sunday in October (changing the clocks to 01:00 GMT), and ends at 01:00 GMT on the last Sunday in March (changing to 02:00 IST).

The following table lists recent past and near-future starting and ending dates of Irish Standard Time or Irish Summer Time (use of DST beyond 2019 is under discussion, see below):

reference

Full Form	Category
Instructional Support Team	Academic & Science
Information Science and Technology	Academic & Science
Information Sciences Technology	Academic & Science
International Study Tour	Academic & Science
Instituto Superior Tcnico (Technical Superior Institute)	Academic & Science
Instructional Systems Technology	Academic & Science
Institute of Space Technology	Academic & Science
Irish Society of Toxicology	Academic & Science
International Students Tours	Academic & Science
Istanbul	Airport Code
Ispat International, N. V.	Business
Information Solutions for Telemedicine	Business
Integrated Service Team	Business
Improvising String Trio	Community
Integrated Services Trunk	Computer and Networking
ISDN tie trunks	Computer and Networking
Innovative Sensor Technology	Computing
Information Services and Technology	Computing
Information and Software Technology	Computing
Institute of Science and Technology	Computing
Integration Services and Technologies	Computing
Institute of Spring Technology	Computing
Information Systems and Technology	Computing
Innovative Sewer Technologies	Computing
Integrated Service Technology	Computing
Innovation Science and Technology	Computing
Institute for Security and Technology	Computing
Information Science Technology	Computing
Industrial Summit Technology	Computing
Interrupt Service Thread	Computing
Instrument Support Terminal	Computing
Integer Store	Computing
International Switched Transit	Computing
Incident Support Team	Computing
Information Society Technologies	Computing
Intelligent Scanning Technology	Computing
Initial System Test	Computing
Integrated Search Technologies	Computing
Interrupt Stack Table	Computing
Immediate Service Termination	Computing
Internal Spanning Tree	Computing
Information Systems Technician	Computing
Information Software Technology	Database Management
Information Sciences and Technology	Educational Degree
Information Systems Technologies	Educational Degree
Information System Technology	Educational Degree
Imaging Systems and Techniques	General
Initial Strength Test	General
Industrial Strength Trance	General
Instituto Superior Técnico	General
India Standard Time	General
Integrated Supply and Trading	General
International Service Team	General
Issaquah Swim Team	General
Inner Space Techniques	General
Inappropriate Sinus Tachycardia	General
International Steam Table	General
Indian Stretchable Time	General
Isolated Seat Tube	General
Idle Shutdown Timer	General
International Super Truck	General
Imperial Stout Trooper	General
Inddiethumpers Standard Time	Governmental
International Sustainability Transitions	International
International Stroke Trial	International
International Surface Technologies	International
Instructional Support Teacher	Jobs
Insulin Shock Therapy	Medical
Intravascular Sono-Therapy	Medical
Institute for Simulation and Training	Military and Defence
Integrated System Test	Military and Defence
In-service Testing	Military and Defence
Interswitch Trunk	Military and Defence
Individual Strength Test	Military and Defence
Information Switching Technology	Networking
Istanbul, Turkey	Regional
Irish Summer Time	Regional
Indian Standard Time	Regional Time Zones
Impact Sports Training	Sports
Integrated Sports Training	Sports
Information Systems Technology	Technology
Irish Summer Time [utc - 0000]	Time
Israel Standard Time	Time