Shedule layouts

You can set the seconds on Schedule New event form, you’d need to adjust the date format in CMS Settings.

so say d-m-Y H:i:s will show you seconds as well.

That being said, creating a lot of very short events isn’t ideal.

It would be much better to manipulate the durations of your layouts so the main layout(s) would have a duration close to 1 hour your ad video layout would stay as it is.
Then you’d have have a campaign with both layouts in it and scheduled that with always daypart to your player.

It would make the schedule page and schedule.xml file on the player much cleaner and would be recommended.