URI
Notation
"3/7"
Caption
Time divisions other than dates in Christian (Gregorian) reckoning
Broader class
"..."  Common auxiliaries of time. Table 1g
Narrower classes
"3"Conventional time divisions and subdivisions: numbered, named, etc.
"4"Duration. Time-span. Period. Term. Ages and age-groups
"5"Periodicity. Frequency. Recurrence at specified intervals.
"6"Geological, archaeological and cultural time divisions
"7"Phenomena in time. Phenomenology of time