HLS playlist has no EXT-X-PROGRAM-DATE-TIME
Without program date-time the stream cannot be mapped to wall-clock time, which breaks DVR seeking and multi-stream alignment.
What it means
Your media playlist declares no EXT-X-PROGRAM-DATE-TIME tag, so segments carry only relative timing.
Why it matters
Anything that needs absolute time stops working: seeking to a wall-clock position in a DVR window, aligning subtitles or a second audio language delivered as a separate rendition, synchronising multiple camera angles, and correlating playback with an EPG. It also makes the live-edge drift check impossible.
How to fix it
- Emit EXT-X-PROGRAM-DATE-TIME at least once per playlist, ideally on the first segment after every discontinuity.
- Use UTC with an explicit offset and millisecond precision.
Check your own stream
The free HLS analyzer runs this check on every analysis and links each finding straight back here.
Open the HLS analyzer →Frequently asked questions
- What does "HLS playlist has no EXT-X-PROGRAM-DATE-TIME" mean?
- Your media playlist declares no EXT-X-PROGRAM-DATE-TIME tag, so segments carry only relative timing.
- Why does it matter?
- Anything that needs absolute time stops working: seeking to a wall-clock position in a DVR window, aligning subtitles or a second audio language delivered as a separate rendition, synchronising multiple camera angles, and correlating playback with an EPG. It also makes the live-edge drift check impossible.
- How do I fix it?
- 1. Emit EXT-X-PROGRAM-DATE-TIME at least once per playlist, ideally on the first segment after every discontinuity. 2. Use UTC with an explicit offset and millisecond precision.
- How can I detect this automatically?
- Paste your HLS streaming URL into StreamTest's free HLS analyzer. It runs this check on every analysis, flags the finding, and links straight back to this page — no sign-up required.
Related HLS checks
- HLS ladder has a bitrate inversionA lower-resolution variant is allocated more bandwidth than a higher-resolution one, so adaptive switching picks the wrong rendition.
- HLS variant is missing the CODECS attributeWithout CODECS, players must download a segment before they can tell whether they can play the rendition at all.
- HLS variant references an undeclared rendition groupA variant points at an AUDIO or SUBTITLES group that has no matching EXT-X-MEDIA entry, which breaks playback on strict players.
- HLS segment is longer than EXT-X-TARGETDURATIONA segment rounds to more than the declared target duration, which violates the HLS specification.
- HLS live window is shorter than three target durationsThe playlist holds too little content, so any player that falls slightly behind runs off the end of the window.
- HLS live edge has drifted from wall-clock timeThe newest segment’s program date-time is far from the current time, meaning the playlist is stale or the clocks disagree.