antirez/redis — pull request #2090 by trauzti (2014-10-22 11:11:25+00:00)
Title: Object ttl command that does not change the object idletime

The regular TTL command sets the idletime to zero. This command returns the TTL in seconds without modifying the idletime.
This can be useful when you are fetching information about objects but don't want to touch them at the same time.