Refund of shore excursion?

[Poconolady]

How far in advance of a Celebrity ships tours starting time do passengers have to cancel and get a refund  of OBC or funds credited back to credit card?

[Mark_K]

REFUNDS AND CANCELLATIONS: Shore Excursions can be cancelled or modified up to 24 hours prior to scheduled tour departure for a full refund. Under no circumstances will refunds be made after an excursion has commenced. Tours involving flights, trains, special events, overnight stays, hotel stays, Celebrity ExclusivesSM, and Private JourneysSM must be cancelled 30 days prior to sailing to avoid cancellation penalties.