Temporal reference is one of the main categories to be tagged. The corresponding category in the tagset is time. The three possible values for the temporal domain tag are present, past and future and are further explained below.
The three main temporal domains are present, past and future. They are defined relative to a given moment, the reference time, by default the time of speaking. In complement clauses, we will assume that the reference time is the time of the matrix event. In the Oceanic languages of Melanesia, the present is often encoded in the same way as the past. The present tense is typically restricted to certain kinds of event structure - it is famously incompatible with perfective aspect.. Therefore, if the event structure is bounded, the temporal reference is typically not present. A possible exception are performatives such as the following:
- Here the story ends. (present, bounded)
In unembedded clauses, classifying temporal reference is usually straightforward:
- Neil went to the zoo. (past)
- Neil is going to the zoo. (present)
- Neil will go to the zoo. (future)
For generic sentences without explicit reference to the past or future, we choose the label present:
- Neil used to go to the zoo. (past)
- Neil goes to the zoo (every Sunday). (present)
- Neil will go to the zoo (every Sunday). (future)
- When/if a flight is cancelled, you get reimbursed. (present)
In embedded sentences, we will classify the temporal orientation of the embedded clause as relative to the time of the matrix clause, not to the utterance time.
- I knew [she would get the job]. (future)
- She wants him [to pass the test]. (future)
- She will think [he had had a bad day]. (past)
Tense in reported speech is treated like embedded clauses, even if it is not explicitly marked as embedded. This means that reported imperatives, for example, are tagged as referring to the future:
- She said: "Wash your hands!" (future)
- He said: "I will wash my hands." (future)
Reference time may be different from the time of utterance. We will not explicitly tag this category, since it does not appear to be marked systematically in our subject languages, but we should keep in mind that it may still play a role. A brief description is added below to illustrate the phenomenon. Temporal meanings are relative to a given reference point. This reference point may be absolute (deictic) or relative (non-deictic). A non-deictic reference point is determined in relation to another event in the same discourse, usually the same sentence. For ease of exposition, we will use the Reichenbachian labels E (event time), R (reference time) and S (speech time).
- Having prepared dinner, Kim proceeded to set the table
- By 3 o'clock, Sue had already arrived.
In the first example, the dinner preparation (E) is in the past not only relative to the time of utterance (S), but relative to the setting of the table (R) — which itself is in the past relative to S (E < R < S). In the second example, 3 o'clock serves as the reference time. By default, R and S are identical and do not need to be differentiated. A reference time that is independent from the utterance time is typically introduced by composite forms involving a participle or similar. Non-deictic forms are not widely attested in Oceanic languages, but we should retain the option to identify them if we come across them.
For the deictic, or absolute, tenses, the default reference time of a main clause is the time of utterance. For an embedded clause, however, the default reference time is the time of the event in the matrix clause. So, the temporal orientation of the embedded clauses of the following examples will be classified as future, even though the described events may have taken place before the time of utterance. In both of the following two examples, therefore, the reference time R is identical with S, the temporal orientation is classified as future:
- I wanted [to arrive early]
- She knew that [she would miss the train]
Yet another case of a deictic tense that does not use the time of utterance as its reference time is the narrative present, as illustrated in the following example.
- Smith was sitting perfectly still behind her rifle. She had spent the entire night setting up with just the right angle for the perfect view on the plaza. She took another look through the lens. A woman was pushing a stroller. A sparrow left the ground fluttered to a nearby tree. [Suddenly, there is a commotion at the corner of her vision]. She moves the lens ever so slightly to get a better look...
In this case, the assumption is that the speech time S has been shifted to the past viewpoint. Such a sentence would therefore be labelled as referring to the present, the reference time R is simultaneous with S.
In many languages, specific markers can have an interpretation that does not simply refer to the past, but signals a certain discontinuity between the past and the present with respect to the described event – something used to be the case, but is no longer the case. 
This is also true for the Daakaka distal when used with reference to the actual past:
|`the life of before was easy, it was easy, but the life of today is hard' (Daakaka.con02:90)|
We will not note this specifically in the tagset, but we should be watchful of signs of discontinuous interpretations and make notes when or if we find them.
Some languages show graded tenses, distinguishing between the near and the more remote past or future. We do not expect to find this in our subject languages but will be mindful of the possibility.
- Bhat 1999. The Prominence of Tense, Aspects, and Mood. John Benjamins
- V. A. Plungian and J. van der Auwera (2006). Towards a typology of discontinuous past marking. Sprachtypologische Universalienforschung 59, 317-349.