Helsinki is 2.5 hours behind Chennai
Best overlap: 11:00 AM to 6:00 PM in Chennai is 8:30 AM to 3:30 PM in Helsinki.
Shoot for 11:00 AM to 6:00 PM in Chennai; your Helsinki colleagues will see that as 8:30 AM to 3:30 PM. Helsinki is 2.5 hours behind Chennai, but with 7 hours of common ground you can hold morning or afternoon meetings without anyone working odd hours. Don't be caught out by clock changes — Helsinki observes daylight saving and Chennai doesn't, so the offset varies by an hour through the year.