#X-START-DATE-TIME Request

I really need this option to allow scheduling by days.

What would be perfect:

```txt
#X-START-DATE-TIME:2026-05-16 11:15:00
blue_10.mp4
#X-START-DATE-TIME:2026-05-16 14:16:20
yellow_10.mp4
```

I need support for full date and time including seconds.

Right now, when scheduling without seconds, some parts of the video can be cropped or skipped, which causes playback issues.

Thanks.
