Amend combobox2 depending on selection from combobox1

[Alpacino]

I have a userform and want to populate combobox 2 depending on selection from combobox 1.
I have months in combobox1 and I have a list of date of week commencing on sheet1.
What will the code be to populate combobox 2 if I select April so combobox 2 will just show dates of wc for April ???

Thanks

 

[Alpacino]

Anyone any ideas please ??