All-Inclusive Honeymoon Packages – Time Sensitive?

My wife and I have been looking at all-inclusive resort packages for January and noticed that some special deals can be had for honeymooners; however, many appear to be time-sensitive, e.g. "must be within 3 months and must provide wedding certificate". Now that's fine and dandy, but it doesn't quite clarify as to whether one must simply "book" the stay within those 3 months, or whether "time of arrival" at the resort must be within those 3 months. Has anyone been through this and do you have any tips/advice in regards to honeymoon resort packages/deals? Thanks a million!