Date.prototype.format = function(format) {    	var o = {        "M+" : this.getMonth() + 1, // month        "d+" : this.getDate(), // day        "h+" : this.getHours(), // hour        "m+" : this.getMinutes(), // minute        "s+" : this.getSeconds(), // second        "q+" : Math.floor((this.getMonth() + 3) / 3), // quarter        "S" : this.getMilliseconds()    	// millisecond    	}    	if (/(y+)/.test(format))        	format = format.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));    	for ( var k in o)        if (new RegExp("(" + k + ")").test(format))            format = format.replace(RegExp.$1, RegExp.$1.length == 1 ? o[k] : ("00" + o[k]).substr(("" + o[k]).length));    	return format;}var begin=new Date();begin.setMonth((new Date().getMonth()-3));//var begintime= begin.format("yyyy-MM-dd 00:00:00");零点格式var begintime= begin.format("yyyy-MM-dd hh:mm:ss");$('#beginDate').val(begintime);