I am probably going to make enemies here, but here in a nutshell is the concept of leave/duty: In the CF, if you are not "on leave", that is do not have an approved leave chit, then you are on duty, even though outside working hours and not otherwise required for duty. The crown is happy to let you go about your affairs as you see fit - subject to recall at any time required, however.
Thus, if you have special plans (I underline special) for a given week-end, or wish to go out of area such as to make your recall difficult or costly, it is up to you to request week-end leave in writing to avoid the unpleasantness of recall. Should your CoC refuse you such week-end pass, heed the warning sign. It is probably because your CoC is aware of circumstances that may lead to recall on that particular week-end.
Those week end pass can also be your butt saver. I always used to put one in when I planned to go to Vancouver for the week-end. Once, BC Ferries decided to can the Sunday night sailings due to a severe storm in Georgia Strait and I had to come back to the ship, late, on the Monday morning. I did not get into trouble, however because Command was aware that I was in Vancouver and therefore wasn't making this up to cover for another reason to be late.