Tail messages change upon an event

Is there away to have the tail messages change upon an event. Right now I am looking to have our repeaters tail messages change for our meeting and then after the meeting go back to on about our net.
What I have worked out right now is in the rpt file for the tail messages to call it /xxx/xxx/xxx/tailmessage
Then in that folder have a bash file to copy and rename the two files to tailmessage.
What I stuck on is scheduling the bash file to only run on a specific day of the month like the second Sunday and then the four Sunday. I would like to do this with a crown job but I don’t think it is possible. If anyone has any ideas that would be great.
Second question is what happens if a tail messages if not there will it play the next if there is one or does it just skip playing any tail messages.

There is no ‘built-in’ method.
You can create your own using ‘on event’ programming.
Or a bash script or both.

I did this with the first public release of ASL ‘ACID’ by just renaming the files with a bash script.
This way the setup config did not need altering
I even added function in the dial plan to turn them on/off by making them unrecognizable by changing the name. They do rotate if you use a tail message list and will skip to the next when one is not seen.
So the trick is only to rename it. I just tagged ‘-off’ tot he end of the filename when I wanted it skipped.tmsg1 tmsg2 tmsg3 etc tmsg3-off would be skipped.

Hope that sparks some ideas to get you where you need to be.