cooling-off period
US /ˈkuːlɪŋ ɔf ˌpɪriəd/
UK /ˈkuːlɪŋ ɔf ˌpɪriəd/

1.
a period of time during which a person is allowed to reconsider a decision or contract without penalty
:
•
Consumers have a 14-day cooling-off period to cancel online purchases.
•
The couple agreed to a cooling-off period before making any major decisions about their relationship.