A time condition (not a group) has a toggle feature code with an associated hint:
*CLI> core show hint *271
*271@timeconditions-: Custom:TC1 State:InUse Presence:not_set Watchers 0
See this post where you can see the value of a hint with
${EXTENSION_STATE(*271@from-internal)}
In this case it will probably return either NOT_INUSE or INUSE.