This is my mistake.
The time on the calendar and in What’s Happening This Week is actually right: due to Daylight Saving Time, this call is now one hour earlier for some: 5:30pm IST | 4pm Nairobi | 3pm Cape Town | 1pm UTC | 9am Boston | 6am Seattle.
(During Daylight Saving Time, 7:30pm IST | 5pm Nairobi | 4pm Cape Town | 2pm UTC is 8am Boston and 5am Seattle)