- // as we don't support DTS_SHOWNONE style so far, we don't allow setting
- // the control to an invalid date, but this restriction may be lifted in
- // the future
- wxCHECK_RET( dt.IsValid(), _T("invalid date") );
+ wxCHECK_RET( dt.IsValid() || HasFlag(wxDP_ALLOWNONE),
+ _T("this control requires a valid date") );