# Periodic tense

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.) or of the year (‘in winter’, ‘in summer’ etc.). 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.$^{:12–14}$

## Periodic tense in Nez Perce

Periodic tense can be illustrated with data from Nez Perce, which has one of the richest paradigms, comprising matutinal, diurnal, vesperal, nocturnal and hivernal, as illustrated in the following examples
méy-tip-se
MAT-eat.meal-PRS:SG
méy-tip-se
MAT-eat.meal-PRS:SG
‘I am having breakfast.’
halx̣pa-típ-sa
DIU-eat.meal-PRS:SG
halx̣pa-típ-sa
DIU-eat.meal-PRS:SG
‘I am eating lunch.’
kulewí·-tip-se
VESP-eat.meal-PRS:SG
kulewí·-tip-se
VESP-eat.meal-PRS:SG
‘I am eating supper.’
te·w-c͗íq-ce
NOCT-talk-PRS:SG
te·w-c͗íq-ce
NOCT-talk-PRS:SG
‘I am talking at night.
ʔelíw-tin̉k-ce
HIB-die-PRS:SG
ʔelíw-tin̉k-ce
HIB-die-PRS:SG
‘I am starving in winter.’

## Reconstructibility

Periodic tense systems are at least partially reconstructible in some language families. 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,$^{:16}$ whose reflexes in Cavineña or the following: diurnal -chinepe, nocturnal -sisa, auroral -wekaka and vesperal -apuna (Guillaume 2008:126).

## Attested subtypes

16 subtypes of periodic tense markers have been identified in Jacques (2023:7, Table 2), with a latinate terminology for each specific time period.
Terminology for periodic tense markers across the world's languages$^{:7}$ :
| Period | Term | Example | Reference |
| at dawn | AURORAL | Cavineña -wekaka | Guillaume (2008:126) |
| in the morning | MATUTINAL | Nez Perce mey- | Aoki (1994) |
| at noon | MERIDIAL | Berik | Westrum (1988:154) |
| in the afternoon | POSTMERIDIAL | May River Iwam -tep | Foley (2018:286) |
| in the evening | VESPERAL | Nez Perce kulewi- | Aoki (1994) |
| in the night | NOCTURNAL | Nez Perce te·w- | Aoki (1994) |
| during the day | DIURNAL | May River Iwam -harok | Foley (2018:286) |
| all day | PANEMERIAL | Chácobo =baina | Tallman (2018: 876–878) |
| all night | PANNUCHIAL | Jarawara =haba | Dixon (2004:136) |
| until dawn | ADAURORAL | Awtuw =alw | Feldman (1986:119) |
| until noon | ADMERIDIAL | Omaha -míthumoⁿshi | Marsault (2021:309) |
| until afternoon | ? | Alamblak -krif | Bruce (1979:275) |
| until nightfall | ADNOCTURNAL | Omaha -hoⁿ | Marsault (2021:309) |
| during winter | HIBERNAL | Arapaho cecin- | Cowell and Moss (2006:217-218) |
| during the spring | VERNAL | Arapaho benii’ow- | Cowell and Moss (2006:217-218) |
| during the summer | ESTIVAL | Arapaho biicen- | Cowell and Moss (2006:217-218) |
| during the fall | AUTUMNAL | Arapaho toyoun- | Cowell and Moss (2006:217-218) |