I ran into a similar problem when working with the Calendar Active X control in developing an application with lots of dates. It took me quite awhile to resolve so am happy to pass along my fix.
My fix involves code on the form which accesses the calendar and on the calendar form itself. However, this may be a bit more than you wanted. Best of luck.
First declare variable in Global, if control is used on more than one form.
Public ctl As Control
The following code is on the form opening the calendar. I made the date field to be updated a command button by using the following code as a "double-click" event.
***Code Start
Private Sub CCStart_Date_DblClick(Cancel As Integer)
'Open calendar form to select date
'First refresh date, in case it was revised
Me.Refresh
'Second, set up variable for active datefield in specified form for calendar lookup/revision
Set ctl = Forms![frmChargeCodes Detail Subform]![CCStart Date]
'The preceding line of code sets up a variable for the control field to be updated.
'Then, Open Calendar
Dim stDocName As String
stDocName = "frmCalendar" 'name of form containing Active X calendar
DoCmd.OpenForm stDocName
End Sub
****End Code
The following code controls what date is presenting on the calendar when it is brought up. The "on load" event On calendar form (which contains the Active X calendar named "GetDate"

determines if the control field on original form is blank and if so, brings up today's date. If not blank, it brings up date of control.
***Code start
Private Sub Form_Load()
'Once calendar form is opened, sets calendar to today's date if date field is empty
If IsNull(ctl) Then
Me!GetDate = Date
Else
'If active datefield is not empty, brings up active date on calendar
Me!GetDate.Value = ctl
End If
End Sub
***Code end
The following code selects date from calendar and populates the control on the form with the new date.
***Code start
Private Sub GetDate_DblClick()
'On DblClick, the active datefield on specified form is changed to calendar date
ctl = Me!GetDate.Value
End Sub
***Code end