Recurrence every week would recur to 1/1, 1/8, 1/15...
Regenerate every week begin on 1/1, then I mark it complete on 1/3, so it regenerates to 1/10, then I mark it done on 1/11th, so it regenerates to 1/18th.
Always regenerating to 1 week after I mark it complete.
CAVEAT: I never use regenerate, so I might be wrong.