direction

This setting must be either older or younger. This setting is used to determine whether indices or snapshots are older or younger than the reference point in time determined by unit, unit_count, and optionally, epoch. If direction is older, then indices (or snapshots) which are older than the reference point in time will be matched. Likewise, if direction is younger, then indices (or snapshots) which are younger than the reference point in time will be matched.

There is no default value. This setting must be set by the user or an exception will be raised, and execution will halt.