Came across this when I accidentally added a workout on the wrong day: It would be nice if when you go into the view/edit screen you could edit the date of the workout as well.
I did the same thing and also think it would be nice to be able to edit the date, rather than delete it from the wrong date and add it to the correct one. While all of this is new to everyone here and we're all learning the ins and outs, and I'm enjoying the concept of the whole thing, I'm finding that the calendar is cumbersome and slow-loading, which is frustrating.