Last time I discussed this with Torben (in the german section of this forums) he was very reserved about this idea.
I had a similar intention due to fixed days like special public holidays that may influence the music or other events liks summer solstice etc.
He proposes to copy (duplicate, not moving) those songs in virtual folders and to refer on them in a summer music template - or similar.
The “don’t schedule before / after” option is thought for campaigns / promos etc. that run a few weeks a year, not repetitive. From his point of view, this is not suitable for music planning or scheduling.
We will review it internally, but from past experience, I’m rather skeptical.
In any case, I have added it to the list of proposals to be discussed.