If you are using ordinary bandages as part of your friction blister care, they need to be changed when they are visibly soiled with blister fluids, dirt or water from the environment (e.g. showering, rain, etc).
You may need to change your bandage anywhere between every hour to once a day but this may vary.
On the other hand, hydrocolloid blister bandages are waterproof, sweat-proof and may stay in place for several days.
For deroofed blisters, specialist blister cushions, like hydrocolloids, only need to be changed when they start to peel off, or when the white bubble formed by the blister fluids underneath the dressing reaches the edge of the cushion.
It’s perfectly fine to leave a hydrocolloid bandage on for several days. Keep your blister cushion in place until the edges start to lift. This could be up to several days. Don’t be tempted to remove them earlier to allow the blister time to heal.