To Enable Multiple Expired Galleries at One Time
This option is helpful when you want to run a sale on previously expired galleries and need to activate many galleries at one time.
Head to the Photos » Galleries page
In the upper right under Quick Filter: choose Expired Galleries
Also in the upper right corner make sure you have chosen the List View option (three lines).
Put a check mark next to any gallery that you want to quickly reactivate.
Click the Actions box in the upper right
Click Change Expiration Date.
Select the date that each of these galleries would expire.
Click Save.
Each of those galleries will automatically be activated and will also expire automatically on the date you selected.