program guide time inconsistency in web app (at least)

[white-haired-uncle]

• Platform:
  Debian13 in a podman container running on Rocky 8.

• MythTV version:

MythTV Version : v36-Pre-518-gab57738caf
MythTV Branch : master
Network Protocol : 91
Library API : 36.20250212-1
QT Version : 5.15.15
Options compiled in:
 linux profile use_hidesyms using_alsa using_oss using_pulse using_pulseoutput using_airplay using_backend using_bindings_perl using_bindings_python using_bindings_php using_dvb using_firewire using_firewire_linux using_frontend using_hdhomerun using_iptv using_satip using_vbox using_ceton using_joystick_menu using_libcrypto using_gnutls using_libdns_sd using_libxml2 using_lirc using_mheg using_opengl using_egl using_qtwebengine using_qtscript using_qtdbus using_sqlite3 using_taglib using_v4l2 using_v4l2prime using_x11 using_system_libexiv2 using_system_libbluray using_system_libudfread using_systemd_notify using_systemd_journal using_drm using_bindings_perl using_bindings_python using_bindings_php using_freetype2 using_mythtranscode using_opengl using_egl using_drm using_vaapi using_nvdec using_vdpau using_qtwebengine using_ffmpeg_threads using_mheg using_libass using_libxml2

I'll be kind of surprised if this is a bug, it's probably something goofy on my end, but might as well capture it.

I just got mythbackend running in a container. I'm sure it's not 100% yet. When trying to schedule my first recording, I noticed that the program I selected that shows in PG at 9:00 said 11:00 in details. Other programs do not do this.
Note the gap in guide data (if I scroll forward in time I do see data for that channel, so it's not the end).
[Ignore that popup for FBI Files, I didn't do that intentionally]

And here we see the program that starts at 9 in the gui shows 11 in details.

Here's the same program on my "real" backend (note how Finding Florida shows in the gui as starting at 11):

which is probably a bit behind the above:

MythTV Version : v36-Pre-515-g60cc32a489
MythTV Branch : master
Network Protocol : 91
Library API : 36.20250212-1
QT Version : 5.15.15
Options compiled in:
 linux profile use_hidesyms using_alsa using_oss using_pulse using_pulseoutput using_airplay using_backend using_bindings_perl using_bindings_python using_bindings_php using_dvb using_firewire using_firewire_linux using_frontend using_hdhomerun using_iptv using_satip using_vbox using_ceton using_joystick_menu using_libcrypto using_gnutls using_libdns_sd using_libxml2 using_lirc using_mheg using_opengl using_egl using_qtscript using_qtdbus using_sqlite3 using_taglib using_v4l2 using_v4l2prime using_x11 using_system_libexiv2 using_system_libbluray using_system_libudfread using_drm using_bindings_perl using_bindings_python using_bindings_php using_freetype2 using_mythtranscode using_opengl using_egl using_drm using_vaapi using_nvdec using_vdpau using_ffmpeg_threads using_mheg using_libass using_libxml2

I also noticed this on the new one. No idea if it's related at all. It's a channel I've never heard of, it's not even in the "real" backend channel list yet, and I haven't even looked into this at all.

[white-haired-uncle]

mythfrontend pointed at the newer backend shows Finding Florida at the correct 11, with no guide data for that channel prior to that time (makes sense, the first mythfilldatabase was probably minutes before 9).

I started thinking maybe because of the missing preceding data, web app was "left justifying" the data (since the gui started at 9pm, it showed the first thing it had starting at 9). Changing to 8:30 seemed to confirm this, but more tests just kind of confused me, like not showing programs that come after Finding Florida - sometimes.

Some screenshots showing different start times in the gui:

[white-haired-uncle]

mythconverg-1384-20250922005352.sql.gz

[bennettpeter]

I suspect this is something to do with time zones. The web app uses the time zone of the browser and shows everything in that time zone. I tried changing the time zone on the computer running the browser, but I could not recreate this problem. Maybe it would happen if the time zone changed while the page was already displayed.

What are the time zone settings on backend container and on the machine running the browser?

[white-haired-uncle]

Both are EDT. I checked that initially, but I figured it would affect all listings, not just the one.

I'm now pretty much convinced it has to do with missing, leading/current, program data. A new test:

MariaDB [mythconverg]> delete from program where title like 'Donkey H%' and subtitle like 'Chili %';

Note how Pinkalicious shifted to the left when I deleted the program before it.

Also note the missing data at 1:30, which does exist in the db. My theory is that web app knows it needs to show the data from 11am-2pm and is doing exactly that - but since there's a hole at the beginning everything is shifted right by a half hour. The 1:30 slot is empty because the data that comes outside the 11-2 range.

This shot shows that the in the gap on the right side does exist. All the times are correct here, I suspect because the guide data that is missing is not in the current display range.

I hope that makes sense. I think I see it, I'm just having a hard time with the words.

[white-haired-uncle]

Ran this again on my real backend. It's a VM, but it eliminates the container. It does the same thing, and it looks like the missing data doesn't have to be at the beginning of the display period, any missing data will shift some stuff left to fill and leave a gap at the end:

MariaDB [mythconverg]> delete from program where title like 'Donkey %' and subtitle like 'Bob Dog%';

MariaDB [mythconverg]> delete from program where title like 'Carl the %' and subtitle like 'The Sticker%';