The company announced on 15 March it would not sail any itineraries across its brands - including Royal Caribbean International, Celebrity Cruises, Azamara and Silversea - until 11 April.
The date has now been moved to 12 May.
RCCL said it was working with guests "to address this disruption to their vacations" stressing how "we are genuinely sorry for their inconvenience".
"We are also working with our crew to sort out the issues this decision presents for them," the company added.
Due to currently announced port closures, RCCL said it expected to return to service for Alaska, Canada and New England sailings on 1 July.
