I don't think that changing your bedding every week end is leaving it too long but it's one of those personal taste questions.
My next door neighbour changes hers every day whereas one of my other neighbours who is a bloke that lives on his own once commented he only changes his when he can be bothered.
Change it about once a week. Do it more often in the summer months.
Nothing like sheets washed and aired and back on the bed in the same day.
Smell and feel wonderful and enhances a better sleep.
I seriously could not be bothered to change our bedding more than once a week, all that laundry! If OH is away and there's only me in it, it might be once a fortnight. More frequently in the summer when we get hotter in the night. Or if it gets hairy from catz moulting....
I know what you mean boxtops, I work 6 days myself but I have about 6 sets of bedding so I don't have to wait on it all drying before putting it on the bed again! lol
Bathmat is washed every 2 days but again I have 4 of them so makes life a bit easier