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.