Every time zone pair we cover, grouped by anchor zone, each with the live offset and the business-hours overlap.
The offset is the easy part
Any search box will tell you that Eastern is three hours ahead of Pacific. What it will not tell
you is that the abbreviation you typed may not be the zone you meant, and that the gap you were told
is wrong for a few weeks a year.
CST is US Central Standard Time and also China Standard Time — fourteen hours
apart. BST is British Summer Time and also Bangladesh Standard Time.
IST means India, Ireland and Israel. And most of these abbreviations name
standard time only: for two-thirds of the year the Pacific zone is on PDT, not PST, so a
meeting set from a page quoting the nominal offset is an hour out. Every page below opens by saying
which zone it means and which offset is actually in force today.
What each page gives you
Today's real offset for both ends, whether either is currently on daylight saving and the date it
next changes, a conversion table for the working day, and the number of hours in which both ends are
actually at their desks — which for some pairs is zero, and is the thing worth knowing before
proposing a time.
Zone rules are set by legislation and change, sometimes at short notice, so every page carries the
data version and a review date. The live converter reads your own browser's copy of the zone
database, so it follows a rule change before we rebuild. To convert a specific time between any two
zones, use the time zone converter.
From Pacific Standard Time (PST)
PST is standard time only. From the second Sunday in March to the first Sunday in November the Pacific zone is on PDT (UTC-7). Most people write PST year-round.
CST means US Central Standard Time (UTC-6) and also China Standard Time (UTC+8) — fourteen hours apart. This page means the US zone. For the Chinese zone see China Standard Time.
GMT and UTC are the same offset but not the same thing: GMT is a time zone, UTC is a time standard. The United Kingdom is on GMT in winter and BST (UTC+1) in summer.
IST means India Standard Time (UTC+5:30), Irish Standard Time (UTC+1) and Israel Standard Time (UTC+2). This page means the Indian zone, which is one of the few on a half-hour offset.
CET is winter time; CEST (UTC+2) applies from the last Sunday in March to the last Sunday in October. Europe changes on different dates from the United States, so the gap to US zones shifts for a few weeks each spring and autumn.
AEST applies in winter; AEDT (UTC+11) applies from the first Sunday in October to the first Sunday in April. Australian seasons are reversed, so summer time runs over the southern summer. Queensland stays on AEST all year.
BST means British Summer Time (UTC+1) and also Bangladesh Standard Time (UTC+6). This page means the British zone, which applies from the last Sunday in March to the last Sunday in October; the rest of the year the United Kingdom is on GMT.