Time Zone Abbreviations: BST, IST, EST and Why They Confuse
Time zone abbreviations are not unique. The same three letters can mean different zones in different countries.
Common clashes
BST is British Summer Time (UTC+1) and Bangladesh Standard Time (UTC+6). IST is India Standard Time (UTC+5:30), Irish Standard Time (UTC+1) and Israel Standard Time (UTC+2). CST is Central Standard Time in North America (UTC-6), China Standard Time (UTC+8) and Cuba Standard Time.
What to write instead
Name the city and add the offset: 15:00 London (UTC+1). Calendar apps that use IANA names, such as Europe/London, always apply the right rules.
Frequently asked questions
Is EST the same as EDT?
No. EST is Eastern Standard Time (UTC-5) and EDT is Eastern Daylight Time (UTC-4). Many people use EST all year when they mean the east coast's current time.
Clock change guides
- What Is Daylight Saving Time (DST)? A Plain-English GuideWhat daylight saving time is, how it works in the UK, Europe and the US, why it exists, its history, who uses it and the argument over scrapping it.
- Why Do the Clocks Go Back in October? The Real ReasonThe clocks go back in autumn to return the UK to GMT, so winter mornings are lighter. The history, the rule, what time it happens and what changes for you.
- When Do the Clocks Go Forward Again After Going Back?When the UK clocks go forward again after the autumn change, how long the UK stays on GMT, when evenings get lighter and how to remember to reset your clocks.