Board Thread:General Discussion/@comment-34911245-20180312143946/@comment-33978305-20180312151540

You can gift repeatedly in the past, but you need to reset your gift counter by going ahead one day (don't do anything in the future though), returning to present day, then going back. You can check your gift counter on the present day to make sure it shows you have sent 0 gifts.

You cannot re-visit friends in the past on days you have already visited, however.

- moon