DFW Daylight Savings Time Transition and ATSC

March 2021

Daylight savings time begins on 14 March which means that stations should begin sending PSIP data to that effect on 15 February. The details on how this process should be managed are in ATSC A/65, Annex A and FCC regulations require that all except low power stations follow the standard.

14 February

After the improved performance last fall when only 3 stations jumped the gun, looking at the data today was dissapointing. Some had already started on the 13th:

WFAA (RF 8)WFAA DST change information

KERA (RF 14)KERA DST change information

KTXD (RF 23)KTXD DST change information

KPXD (RF 25)KPXD DST change information

KMPX (RF 30)KMPX DST change information

KAZD (RF 31)KAZD DST change information

With more today:

KDFI (RF 27)KDFI DST change information

KDTN (RF 29)KDTN DST change information

KDAF (RF 32)KDAF DST change information

17 February

Power and DSL service went out Monday so I haven't had a change to update this till now. This long list of standard violations was enough to send my DTVPal DVR over the edge and switch into DST early resulting in several scheduled recordings happening at the wrong time. Right up till power went out at 6:45AM.

Today I look and see most stations with the requisite data showing a transition on the 14th at 2AM. With 4 notable exceptions. The 3 stations that changed their time by 3600 seconds last fall when exiting DST have done nothing. KDFW (The local FOX affiliate so the really should know better.) is still claiming we are in DST but also showing a transition happening at midnight on the 1st of the month.

14 March

Many stations performed the transition this morning as expected but there were exceptions. KFWD, KDTX, and KAZD dropped the day and hour yesterday at 8PM and set the DST flag at 2AM (CST). A problem if you want to use their guide data to see what was on.

KDTX (RF 21)KDTX DST change information

KDTN's PSIP data was messed up for a couple ofhours so perhaps that is why they dropped the DST information at 8PM for a bit.

KDTN (RF 29)KDTN DST change information

The four stations that changed their GPS time by an hour instead of doing anything at all to the DST data reversed that today. KHPK, KNAV, K07AAD, and KODF removed 3600 seconds of offset in their time. Leaving the DST_status flag alone and still indicating out of DST.


I have been doing this since 2015 and previous versions of this page can be found at the Internet Archive. I have archived the raw data and can provide it on request.

ATSC Monitoring