Chennai is 12.5 hours ahead of Vancouver

There is no standard 8-to-6 overlap. Someone joins early or late.

A 12.5-hour difference puts Vancouver and Chennai out of sync — when one team is mid-morning, the other is fast asleep. Consider rotating the inconvenience: one week Vancouver takes the early call, the next week Chennai does. Remember that Vancouver shifts for daylight saving and Chennai doesn't, so recalculate the overlap after each clock change.