Hide and unhide columns according to number of days in my calendar

[djemy1975]

Hi friends and developpers,

Please could you help me on this small program to follow-up trainees according to a specified calendar.

What I want to do is :

In "Trainees planning sheet ",I would like to hide and unhide columns (AH,AI,AJ) when I filter by month and date ,from dropdowns on the left, according to the number of days in each month and year.

Is there any vba module that could do the trick?

Please help as I am stuck in this problem since many days ago.

Herewith a file you could work on:

Best regards,