I spend a lot of time to finally find a cause about the scheduler. I'll explain you how to reproduce these bugs.

Before starting, perform a fresh install of Airtime*.

Do : sudo apt-get purge airtime airtime-easy-setup apache2 icecast2 && sudo apt-get autoremove --purge

then reinstall Airtime.

1st Bug : Content disappear after a certain date

1. Create a dynamic smart block.

For example, ~1000 tracks, duration 1 hour.

2. Create a show.

Duration : 1 hour.
Repeat : Mon-Sun (everyday).
Link : YES (important).
End date : At least 2 month, for example 30/09/2014.

3. Go to calendar, mode week then click 'today'.

Click on the show, and add content with the smart block created previously.

4. Go to calendar again.

Click on the show, 'Edit > Edit show'.
Uncheck 'Link' (a message appears to say it's not possible to re-link the show).
Update show.

5. Do several clicks on the 'next week' button (left of the 'today' button).

At a moment you will see that the content disappeard!

2nd Bug : Content became the same every day

1. Create a dynamic smart block.

For example, ~1000 tracks, duration 1 hour.

2. Create a show.

Duration : 1 hour.
Repeat : Mon-Sun (everyday).
Link : YES (important).
End date : At least 2 month, for example 30/09/2014.

3. Go to calendar, mode week then click 'today'.

Click on the show, and add content with the smart block created previously.

4. Go to calendar again. Do several clicks on the 'next week' button (left of the 'today' button).

You should see now the same content on every show.

*Why I say to do a fresh install of Airtime :

After these steps, try wipe the calendar by :

sudo -u postgres psql airtime -c "delete from cc_show"

If you reproduce these steps exactly, you will see that these bugs don't reappears!

I hope these informations will help developpers to fix these bugs now!