Hi there, you would need to create a Power Automate flow to achieve this.
Couple of approaches: 1) Create a Power Automate that triggers on creation of a new SharePoint List Item, then enter a Delay action for the number of days, followed by an update Item action that sets the value back. Note, if the number of days is approaching 30, then the Power Automate will timeout...so move to option 2:
2) Create a Power Automate flow with a daily recurrence trigger (i.e. a Scheduled flow), query the list using the Get Items actions, filtering items by comparing the utcnow expression to the CreatedDate, then iterate through items using a For Each action and update the items accordingly