6710 			var ndate = new Date(date.valueOf());
6712 			ndate.setDate(ndate.getDate() + inc);
6713 			if (inc >= 0 && (!date.getHours() && ndate.getHours()) &&//shift to yesterday on dst
6714 …(ndate.getDate() <= date.getDate() || ndate.getMonth() < date.getMonth() || ndate.getFullYear() < …
6715 				ndate.setTime(ndate.getTime() + 60 * 60 * 1000 * (24 - ndate.getHours()));
6716 			return ndate;
6721 			var ndate = new Date(date.valueOf());
6724 					ndate = this._add_days(ndate, inc);
6727 					ndate = this._add_days(ndate, inc * 7);
6730 					ndate.setMonth(ndate.getMonth() + inc);
6733 					ndate.setYear(ndate.getFullYear() + inc);
6746 					ndate.setTime(ndate.getTime() + inc * 60 * 60 * 1000);
6750 					ndate.setTime(ndate.getTime() + inc * 60 * 1000);
6756 			return ndate;
6877 		getISOWeek: function (ndate) {  argument
6878 			return gantt.date._getWeekNumber(ndate, true);
6880 		_getWeekNumber: function(ndate, isoWeek){  argument
6881 			if (!ndate) return false;
6882 			var nday = ndate.getDay();
6888 			var first_thursday = new Date(ndate.valueOf());
6889 			first_thursday.setDate(ndate.getDate() + (4 - nday));
6896 		getWeek: function(ndate){  argument
6897 			return gantt.date._getWeekNumber(ndate, gantt.config.start_on_monday);
6899 		getUTCISOWeek: function (ndate) {  argument
6900 			return gantt.date.getISOWeek(ndate);