How to make drop-down menu of months in schedule,when сhoose it - columnes are added?

[Huawei]

Please if someone could help me, how to make a drop-down menu of months in the schedule, and when you сhoose a specified month - day columnes are added in the schedule automatically???
I need only the new columns to be inserted depending on the lenght of the month, like when I choose Fabruary from the central drop-down menu (I attached the file template february.zip, please check it out) there must be 28 days inserted, when I choose March - there must be 31 days (more columnes) inserted, for April - 30 days and so on. As for schedule data like time of shifts - I will do it myself , no need automatically to be filled in.
Please if someone could help me, how to do it????