If that is your half time, you will not require proof of time.
Proof of time is required for a sub-5:30 full or a sub-2:15 half. So if you anticipate to finish in MORE time than that for either event, no proof of time is necessary.
However--for those with sub-times or close times....you can use any event between now and Disney and submit it. I believe you can just bring it to Expo and they will adjust your corral.