It will be. Islamic events are scheduled by a lunar calendar, which has less days in a year than our solar calendars. So things like the fasting in Ramadan and the pilgrimage are about 11 days earlier each year. So in like 12 years the Hajj should be during February.

I’m no expert, but I think the events the pilgrims attend to are strictly tied to the time of day, meaning they can’t be rescheduled to be in the night.