A 365/366 Challenge is a type of Challenge Cache.
In a 365/366 Challenge, the goal is to find a geocache for each day of the year. To order to log a find on one of the 365/366 Challenges, a geocacher must geocache every calendar day of the year. Now one might be thinking there are only 365 days in a year, why a 366 version? The 366 version accounts for the leap day that occurs every four years. This makes the 366 version slightly harder to complete if one misses that leap day. Challenge owners will typically specify if the challenge is a 365 or a 366 challenge, though some may allow both on a single challenge.
Most 365/366 challenges require finds on all 365/366 calendar days. However, other variations have popped up. One such variation requires geocachers to find caches that are hidden on all 365/366 calender days. In other words, it doesn't matter what day the cache was found, only what day the cache was hidden.
Specific rules may vary from owner to owner, but the common rules involve:
- Finds made prior to the publication of the challenge are allowed.
- All finds must be either (depending on the challenge):
- Found on each calendar day of the year
- Hidden on each calendar day of the year
- All cache types count