The BeforeDrawDayViewCell event must be used when you want to change the background's cell color.

The problem is :  This event has no effect if your calendar has a Theme (like office 2007)...

 

 

For example to change the background cell for lunch time:

 

Private Sub Calendar_BeforeDrawThemeObject(ByVal eObjType As XtremeCalendarControl.CalendarBeforeDrawThemeObject, ByVal DrawParams As Variant)
    
    Dim pTheme2007 As CalendarThemeOffice2007
    Set pTheme2007 = Calendar.Theme
   
    If eObjType = xtpCalendarBeforeDraw_DayViewCell Then
        Dim pCell As CalendarThemeDayViewCellParams
        Set pCell = DrawParams
        If Not pCell.Selected Then
           
        If TimeValue(pCell.BeginTime) >= CDate("12:00") And TimeValue(pCell.BeginTime) < CDate("14:00") And Weekday(pCell.BeginTime) <> 1 Then
            pTheme2007.DayView.Day.Group.Cell.WorkCell.BackgroundColor = pTheme2007.DayView.Day.Group.Cell.NonWorkCell.BackgroundColor
        End If
       
        End If
    End If

 

End Sub

 

Perhaps, it could help you do the trick.

 

 

The challenge is that you want to customize a first calendar control (Appointments), from a second table of calendar events (employee schedule).

 

I think that the best way is to open the Employee Schedule in a calendar control, and use RetrieveDayEvents Method to get all the events of the date concerning (all events recurring or not) and customize the second calendar control (Appointments) with the data retrieve in the first one, with BeforeDrawThemeObject event (do only one RetrieveDaysEvents read for each day).

 

You can also lock modifying, and creating event  to not cover the red block event by testing EndTime and StartTime of the event in the EventAdded or EventChanged events.

 

 

Here some codes to explain more the method:

 

Calendar1 is the Employees Calendar, Calendar2 is the Appointment Calendar.

 

' *** Global variables to avoid to read the Employees Calendar every time cell Appointment Calendar is drawing 

Dim DtT As Date, StartT As Date, EndT As Date

 

' *** The BeforeDrawThemeObject Event

Private Sub Calendar2_BeforeDrawThemeObject(ByVal eObjType As XtremeCalendarControl.CalendarBeforeDrawThemeObject, ByVal DrawParams As Variant)
   
    Dim pTheme2007 As CalendarThemeOffice2007
    Set pTheme2007 = Calendar2.Theme

 

    If eObjType = xtpCalendarBeforeDraw_DayViewCell Then
        Dim pCell As CalendarThemeDayViewCellParams
        Set pCell = DrawParams
        If Not pCell.Selected Then
           
        If OnlyDay(DtT) <> OnlyDay(pCell.BeginTime) Then ReadBreaks pCell.BeginTime
       
        If pCell.BeginTime >= StartT And pCell.BeginTime < EndT Then
            pTheme2007.DayView.Day.Group.Cell.WorkCell.BackgroundColor = vbRed
        End If
       
        End If
    End If

 

End Sub

 

' *** The sub to retrieve the red time block in the first calendar (red event is supposed to have a label property to 1, this can be changed of course). Only one red time block is supposed by day.

Sub ReadBreaks(Dt As Date)
Dim CollDayEv As CalendarEvents
Dim Evt As CalendarEvent
Dim i As Long

 

    StartT = 0
    EndT = 0
    DtT = Dt
    Set CollDayEv = Calendar1.DataProvider.RetrieveDayEvents(Dt)
    With CollDayEv
        If .Count > 0 Then
            For i = 0 To .Count - 1
                Set Evt = .Event(i)
                If Evt.Label = 1 Then
                    StartT = Evt.StartTime
                    EndT = Evt.EndTime
                    Exit For
                End If
            Next
        End If
    End With
End Sub

 

' *** Just a function to get only the day from date variable.

Function OnlyDay(ByVal Dt As Date) As String
    OnlyDay = Format(Dt, "dd/mm/yyyy")
End Function