Some geocache types have the ability to automatically lock the geocache from new logs and archive the geocache after a certain number of days.
An ephemera geocache can be "live" for a maximum of 7 days including the hidden date. After that it will be automatically archived and new found logs will not be permitted. Editing of other logs types will be permitted but cannot be changed to a found log type. This ensures that a limited life geocache is logged within the time of of it life.
For example an ephemera geocache is hidden on Saturday 1st June. Setting the lock days to 1 will mean the geocache is live for the remainder of Saturday 1st June ONLY. Setting the lock days to 2 will mean the geocache is live for the remainder of Saturday 1st June AND Sunday 2nd June.
The system will default to 2 days allowing a 2 days to log the geocache before it is locked. i.e. A normal 2 day weekend.
When choosing the number of days, make sure you leave enough time for people to make their logs before the geocache is locked. Ask yourself whether 1 day is enough time to log your geocaches if your event finishes at 5:00pm and the geocache is locked that same midnight.