Periodic tense is a subtype of the grammatical category of tense, which encodes that the event expressed by the verb occurs within a particular period of the day (such as ‘at night’, ‘in the morning’ etc.)
[1] Its does not encode a relation to a particular point of reference, unlike deictic tense, the grammatical expression of time reference (usually past, present or future) relative either to the moment of speaking (absolute tense) or to another point of reference (relative tense).
Periodic tense is geographically restricted to Northern America, the Western Amazon region, the Sepik region, Arnhem land and it is almost entirely absent from languages of Africa and Eurasia, which the exception of Chukotkan languages.
In proto-Sahaptian for instance, nocturnal *têw- and matutinal *mêy-, from which Nez Perce nocturnal te·w- and matutinal méy- above originate, have been reconstructed by Aoki (1962).
In Tacanan languages, four periodic tense markers are reconstructible,[1]: 16 whose reflexes in Cavineña or the following: diurnal -chinepe, nocturnal -sisa, auroral -wekaka and vesperal -apuna (Guillaume 2008:126).