It is very possible to send a value between userforms. Consider defining
Userform Properties. Make sure that you copy the property from the
frmCalendar to the frmLoaner before Unloading it.
Also, using properties, you can build the frmCalendar in a way that it
return dates however often it is needed per form. That's a very good idea.
Perhaps you could call it as a function:
frmLoaner.txtAnyTextbox.Value = frmCalendar.Date
I know this is just conceptual at this point, but you should be able to set