The Elder Scrolls V: Skyrim Tips

Skyrim's Refresh, Respawn and Restock Durations
As with previous Bethesda games, certain things such as harvested items, stores, containers and enemy spawns, will 'refresh' at certain intervals. Stores will take roughly 2 to 3 days to restock their goods and gold, whilst previously cleared areas of enemies take roughly 3 to 5 days.