The descriptor instantiationTimeStart provides a time stamp for the beginning point of playback for a time-based media item, such as digital video or audio. Use in combination with instantiationDuration to identify a sequence or segment of a media item that has a fixed start time and end time.


/ pbcoreDescriptionDocument / pbcoreInstantiation / instantiationTimeStart



1 time or less

May Contain:

Contained by:

Contained with:

[Any elements used MUST appear in this relative order]


  • <instantiationTimeStart>00:23:30:15</instantiationTimeStart>


PBCore recommends flexibility in expressing time stamps. Radio producers often prefer the simple HH:MM:SS designation. Television producers prefer the SMPTE time code standards HH:MM:SS:FF. Some multimedia architectures express time in HH:MM:SS.mmm, where the mmm represents milliseconds.

Consequently, the best practice is to match the time stamp designation to your preferred method:

  • HH:MM:SS
  • HH:MM:SS.mmm
  • HH:MM:SS:FF (SMPTE Timecode nondrop frame-NTSC)
  • HH;MM;SS;FF (SMPTE Timecode drop frame-NTSC)

One response to “instantiationTimeStart”

  1. Marcos Sueiro

    It is unclear to me how to use this element without a corresponding reference at the asset level, unless it is implied that the complete asset starts at 00:00:00, in which case it should be specifically pointed out in the description here.
    In the example above, it is unclear what 00:23:30:15
    refers to. 23:30:15 from what?

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