In the graph below you see the time zone difference between India Standard Time and Eastern Daylight Time. Drag the bubble to adjust the time and to see the corresponding time in the other time zone.
India Standard Time is the time zone of India, including cities like New Delhi, Mumbai, Bangalore, Kolkata and Colombo. Eastern Daylight Time is the time zone of the Canadian and US East Coast when observing daylight saving time in the summer, with places like Montreal, Ottawa, New York, Washington D.C. And Miami.
Usually it is preferable to schedule meetings in the late afternoon for the person in IST and before lunch for the person in EDT.
India, Sri Lanka
Delhi, Colombo, Kolkata and Mumbai
This timezone does not observe daylight saving time so the time difference always stay the same. You however need to pay attention to if the other time zone is observing DST as this will make a difference.
IST can also refer to Irish Standard Time or Israeli Standard time, but most of the times it is India that is being referred to – just make sure to double check this before you send that calendar invite!
This is the summer time of the Eastern US, Canada and parts of the Caribbean. It is in effect between March and October for most locations and is four hours behind UTC. It is important to note that even within certain states, e.g. Florida, Michigan, and Tennessee there are locations that do NOT observe EST/EDT but instead belong to other time zones. The same goes for the Canadian provinces Ontario and Quebec.
Most of the Eastern seaboard of the US observe Eastern Daylight Time, as well as most locations in Eastern Canada although there are a few exceptions. Locations such as New York, Washington, Quebec and Ontario are all on Eastern Standard Time. Also some Caribbean locations such as Jamaica, Haiti and Panama are in this time zone.
With the exception of Panama, Jamaica and a couple of locations in Canada and the US daylight saving time is observed. Unless you are sure that the location you have in mind is truly in EST/EDT it is always better to use the exact location name rather than the time zone abbreviation.