Every week here as well: cotton fitted bottom sheets, flat top sheets and pillowcases.
Duvet cover is changed every three weeks as it's decorative rather than functional.
If I ever have a restless night's sleep it's usually when the beds need changing.
Don't iron anything though; tumble dry the fitted sheets, dry the rest on a big airer (outdoors if possible), fold carefully and put away.
inishowen I knew a student who proudly told his mum he'd changed his sheets, just like she'd nagged him to.
Turned out he hadn't washed the old set though, just folded them and put them away! ?♀️