A period of time past the deadline for fulfilling an obligation during which a penalty that would be imposed for being late is waived, especially an extended period granted as a special favor Open English WordNet

A grace period is a period immediately after the deadline for an obligation during which a late fee, or other action that would have been taken as a result of failing to meet the deadline, is waived provided that the obligation is satisfied during the grace period. Wikipedia

Extra time to fulfill an obligation Wikipedia Disambiguation

Period immediately after the deadline for an obligation during which a late fee is waived Wikidata

A length of time during which rules or penalties do not take effect or are withheld. Wiktionary