Proposal. Reverse autofill move

[TimChebotarev]

Hey there!

I would like to propose to add reverse autofill mode. When you change finish time it change start date accordingly.
Also It can be really helpful for certain scenarios if I as user is able to fix Start or Finish time to set the order for the schedule.

Ex. I know the time my train departs, so I can calculate all my entire schedule from the time of departure to time when I should start preparing exactly in this order.

Anyway, thanks for nice and useful plugin. 🙏🏻