IST to EST Converter

The gap is 9.5 or 10.5 hours, depending on the date

India Standard Time sits 5.5 hours ahead of UTC and never changes. New York alternates between Eastern Standard Time at UTC-5 in winter and Eastern Daylight Time at UTC-4 in summer. The difference between the two cities is therefore 10.5 hours for most of the northern winter and 9.5 hours for most of the summer.

The switch happens on US dates, not Indian ones: the second Sunday in March and the first Sunday in November. For roughly three weeks in March and one in late October, the US has changed its clocks and Europe has not, which is why a call involving London as well can drift in a way that surprises people who only track one of the two transitions.

Strictly, "EST" names only the winter half of the year; the summer half is EDT, and "ET" covers both. In practice most people write EST year round. The converter above shows whichever is actually in force on the date you pick, so you do not have to decide which acronym was meant.

Where the two working days meet

With a nine-to-six day at both ends, the overlap is the Indian evening against the New York morning. From about 6:30 PM to 8:00 PM in Bengaluru you have roughly 9:00 AM to 10:30 AM in New York, and that narrow band is where most India-US East calls end up.

The gap widens slightly in the summer, when the difference drops to 9.5 hours and the overlap starts half an hour earlier in Indian terms. If your team can stretch to a 6:00 PM start in India, the summer months give you a genuinely comfortable window; the winter version is tighter and tends to push into the Indian evening.

• 9:00 AM New York is 7:30 PM in Bengaluru during US daylight saving, 6:30 PM outside it.
• 6:30 PM Bengaluru is 9:00 AM New York in winter, 8:00 AM in summer.
• A 30-minute call at 6:30 PM India lands inside the New York morning all year.

Mistakes that cause missed calls

The half hour is the most common one. India is at a 30-minute offset, so a mental shortcut of "ten hours" is wrong half the year and half an hour off the rest of it. The second is assuming the gap is fixed: a recurring call scheduled in November and still running in April has moved by an hour relative to one of the two participants.

The third is the date boundary. A 10:00 PM call in Bengaluru is the same day in New York, but a 7:00 AM call in Bengaluru is the previous evening there. When the calendar dates differ, say both dates explicitly in the invite rather than only the time.