var condition1 = new GcSpread.Sheets.DateCondition(GcSpread.Sheets.DateCompareType.AfterEqualsTo, new Date(2012, 11, 31));
var condition2 = new GcSpread.Sheets.DateCondition(GcSpread.Sheets.DateCompareType.BeforeEqualsTo, new Date(2013, 11, 31));
var nCondition = new GcSpread.Sheets.RelationCondition(GcSpread.Sheets.RelationCompareType.And, condition1, condition2);
var validator = new GcSpread.Sheets.DefaultDataValidator(nCondition);
activeSheet.getCell(0, 0, GcSpread.Sheets.SheetArea.viewport).dataValidator(validator);
spread.highlightInvalidData(true);
activeSheet.setValue(0, 0, new Date(2012, 11, 25));