Certified GKH Gardening Expert
This will depend on the bulb. You must dig them up while they are in dormancy, then keep them in dormancy until their specific time to plant. This is dependent on the plant, also.
Here is an article that will help you to store bulbs until they are ready to plant: https://www.gardeningknowhow.com/ornamental/bulbs/bgen/preparing-bulbs-for-winter-how-to-store-bulbs-for-winter.htm