That would vary, on how much current is drawn through the fuse at switch on (as this is the heaviest), and how many times a day it’s turned on an off.
How often (time period) do you recommend changing fuses to new ones?
If they’re only $2 do them every 6mts or so.
https://www.digikey.com.au/products/en/circuit-protection/fuses/139?k=fuses&k=&pkeyword=fuse...
Cheers George