It seems to me that you have a lot of OR conditions for a Constraint but to answer your question. Your logic should break into this if you use named queries. Save your first query eg Query1 and the second eg Query2. Use names that are meaningful to you and adjust the code accordingly.
Code:
Sub twoqueries()
On Error GoTo twoqueries_Error
If Time() < #10:00:00 AM# Then
Debug.Print "Less than 10" & Time() & " so run Query1"
'Docmd.openQuery("Query1")
Else
Debug.Print "Greater than " & Time() & " so run Query2"
'Docmd.openQuery("Query2")
End If
On Error GoTo 0
Exit Sub
twoqueries_Error:
MsgBox "Error " & Err.number & " (" & Err.Description & ") in procedure twoqueries of module4"
End Sub
You would remove the ' to activate the commented lines.
??? What happens if it is exactly 10:00:00 AM????