格式化日期串兼容ie8以下
http://www.webdeveloper.com/forum/showthread.php?t=247673
function formatDate(date){ var h = date.getHours(); var n = date.getMinutes(); return (h < 10 ? '0' + h : h) + ':' + (n < 10 ? '0' + n : n);}function formatDateStr(dateStr){ var d = new Date(dateStr); if(isNaN(d)){ var rx = /^(\d{4}\-\d\d\-\d\d([tT][\d:\.]*)?)([zZ]|([+\-])(\d\d):(\d\d))?$/; var p = rx.exec(dateStr) || []; if(p[1]){ var day= p[1].split(/\D/); for(var i=0,L=day.length;i<L;i++){ day[i] = parseInt(day[i], 10) || 0; }; day[1] -= 1; day = new Date(Date.UTC.apply(Date, day)); if(!day.getDate()) return NaN; if(p[5]){ var tz = (parseInt(p[5], 10)*60); if(p[6]) tz += parseInt(p[6], 10); if(p[4] == '+') tz *= -1; if(tz) day.setUTCMinutes(day.getUTCMinutes() + tz); } return formatDate(day); } return NaN; } return formatDate(d);}