For the vast majority of activities, you can book right up until 1 hour before the activity starts. On the other hand, if you want to book weeks or months in advance, you can do that also.
Occasionally, some Activity Providers may require you to book before midnight on the day before the Activity takes place as they need the extra time to prepare equipment, safety and other things for your Activity.
Activities that are not bookable for these reasons will not show up in your App Search Results, so the best way to think about it is this: if you can see it in your search results, you can book it!
If you still need help, please Contact Us