private void Form1_Load(object sender, EventArgs e)
        {
            System.Globalization.DateTimeFormatInfo dtf = new System.Globalization.DateTimeFormatInfo();
            dtf.LongDatePattern = "D";
            dtf.ShortDatePattern = "M/d/yyyy";

            FarPoint.Win.Spread.CellType.FilterBarCellType fbcell = new FarPoint.Win.Spread.CellType.FilterBarCellType();
            fbcell.AutoFormat = true;
            fbcell.ContextMenuType = FarPoint.Win.Spread.CellType.FilterBarContextMenuType.DateTime;
            fbcell.DateTimeFormatInfo = dtf;
            fpSpread1.Sheets[0].AutoFilterMode = FarPoint.Win.Spread.AutoFilterMode.FilterBar;
            fpSpread1.Sheets[0].FilterBar.Cells[0].CellType = fbcell;
            fpSpread1.Sheets[0].Cells[0, 0].Value = DateTime.Now;
}

        private void fpSpread1_FilterBarDropDownSelectionChanging(object sender, FarPoint.Win.Spread.CellType.FilterBarDropDownSelectionChangingEventArgs e)
        {
            if (e.ChangesObject is string) //all condition to Contains using wildcard
            {
                // e.ChangesObject = "*" + e.ChangesObject.ToString() + "*";
                //e.Handled = true; //notify to use new changed value
            }
            else if (e.ChangesObject is DateTime) //change DateTime to a short format string
            {
                //e.ChangesObject = ((DateTime)e.ChangesObject).ToShortDateString();
                FarPoint.Win.Spread.CellType.DateTimeCellType dc = new FarPoint.Win.Spread.CellType.DateTimeCellType();
                dc.DateTimeFormat = FarPoint.Win.Spread.CellType.DateTimeFormat.UserDefined;
                dc.UserDefinedFormat = "M/d/yy";
                //e.ChangesObject = dc.Format(e.ChangesObject);
                GrapeCity.Win.Spread.InputMan.CellType.GcDateTimeCellType datecell = new GrapeCity.Win.Spread.InputMan.CellType.GcDateTimeCellType();
                GrapeCity.Win.Spread.InputMan.CellType.Fields.DateDayFieldInfo test = new GrapeCity.Win.Spread.InputMan.CellType.Fields.DateDayFieldInfo();
                datecell.FocusPosition = GrapeCity.Win.Spread.InputMan.CellType.FieldsEditorFocusCursorPosition.MouseLocation;
                datecell.Spin.AllowSpin = true;
                datecell.Spin.IncrementValue = new TimeSpan(2);
                datecell.DropDownCalendar.BackColor = Color.Red;
                datecell.DropDownCalendar.CalendarDimensions = new Size(3, 1);
                datecell.DropDownCalendar.Font = new Font("Arial", 10, FontStyle.Bold);              
                datecell.DropDown.AllowDrop = true;
                datecell.DropDown.AllowResize = true;
                datecell.DropDown.AutoDropDown = true;
                datecell.DefaultActiveField = datecell.Fields[2];
                e.ChangesObject = datecell.Format(e.ChangesObject);
                e.Handled = true; //notify to use new changed value
            }
            else if (e.ChangesObject is Color) // change color or icon enumerable
            {
                if (((Color)e.ChangesObject) == Color.Red) e.ChangesObject = Color.DarkBlue;
                e.Handled = true; //notify to use new changed value
            }
            else //by default it is false, not used
                e.Handled = false; //notify to not use new changed value
        }