@Taris #VoreThursday has been a thing for years, origination because of furmeets on Thursdays that tended to have an abundance of vore attendance.

That, and it perfectly led into FatFriday (Tag removed so sensitive fatties don't find this). WideWednesday was also a thing for awhile.
Not sure if vore related, but MpregMonday was sometimes joked about being a reformation process to prepare for the next vore week.

Anywho, this is the history I know of; the one I feel strongly on is Thursday. X3