As long as the hash browns are properly stored in the refrigerator the has browns should last from 5 to 7 days in the refrigerator.
To extend the life of the hash browns in the refrigerator the hash browns should be stored in a shallow airtight container or resealable bags.
If you want to keep the hash browns longer than 5 to 7 days you should freeze the hash browns instead of refrigerating them.
When you freeze the hash browns the hash browns will last up to 12 months when kept frozen and sometimes longer.
Freezing the hash browns keeps mold and bacteria from growing on the hash browns.