1 Definition 2 Functional Requirements 3 Syntax 4 Semantics

1 Definition

Time Qualifier is a set of data providing additional information on Time Data for potential use by a machine.

The combination of Time Data and Time Qualifier is called a Time Object or simply Time, specified by MPAI-OSD V1.5.

2 Functional Requirements

Time Qualifier must allow the expression of the following elements:

  • Kind: Specifies the semantic type of Time (point, interval, duration).
  • IntervalForm: Specifies the structure of an interval (startEnd, startDuration, durationEnd).
  • Formats: Specifies the syntax used to encode Time Data (e.g., ISO 8601, SMPTE, MIDI/MTC).
  • Attributes:
    • Recurrence: Defines how often the Time applies.
    • Exceptions: Defines events excluded from recurrence.

Users needing additional entries in the Time Qualifier or support for new Qualifiers should make a documented request to the MPAI Secretariat. Requests will be considered by the appropriate MPAI committee.

3 Syntax

https://schemas.mpai.community/TFA/V1.5/data/TimeQualifier.json

4 Semantics

  • Kind:
    • point: A single time instant.
    • interval: A span of time expressed as start/end, start/duration, or duration/end.
    • duration: A length of time without a fixed start or end.
  • Formats:
    • MPAI-OSD V1.5 SimpleTime
    • Other Formats:
      • SMPTE 12M-1
      • SMPTE 12M-2
      • MIDI/MTC
      • ISO 8601
      • IETF RFC 3339
  • Attributes:
    • Recurrence: Time elapsed until a new event occurs.
    • Exceptions: Events excluded from recurrence.

Note: EndTime and Duration are not separate attributes in TimeQualifier. They are encoded inside Time.Data according to the chosen Kind and IntervalForm (e.g., ISO 8601 start/end or start/duration).

P: Indicates the start of the duration (“Period”).
Y: Year designator (e.g., 1Y for one year).
M: Month designator (e.g., 2M for two months).
W: Week designator (e.g., 3W for three weeks).
D: Day designator (e.g., 4D for four days).
T: Time designator, which precedes the time components.
H: Hour designator (e.g., 5H for five hours).
M: Minute designator (e.g., 6M for six minutes).
S: Second designator (e.g., 7S for seven seconds).