Well, FWIW, whenever I hear about 'calendar control', it's usually in scorn rather than praise and indeed if one googles a bit, some Access developers basically encourage shunning it although and using API calls instead to avoid the inherent problems in calendar control. Many developer likewise try to avoid using ActiveX controls for similar reasons.
I'm sorry that you're in this unfortunate situation but I honestly can't see how this is not a good thing that Access now has a native calendar control built-in, thus freeing you & me & any other developers of the usual headaches that comes with the litany of solutions/workarounds we dealt with the old calendar controls or API calls.
I think the main reason is that Microsoft wants to move away from COM and ActiveX technology - in fact, there will be no 64-bit version of calendar version or treeview control or other controls that comes in the comctl.ocx. So while Access is definitely moving ahead into 64-bit world, it'd be better off to do without technology that are no longer blessed by Microsoft.