Try declaring a global object variable in a module, to represent any of your 20
date labels as needed:
Global WhichOne as Object

Then, in Date1_Click(), add
Set WhichOne = frmBrkDown.LabelDate1
before loading your calendar  form. You must
make a similar change for each of your other Date_Click subs.

Change your calendar form  code to
WhichOne.Caption = cal.value
Unload Me