注：引數解釋 symbol 時間之間的分隔符例如 '-'、'/';  n 數字;  當前時間:2016-11-26

1.獲取今天的日期

     function getTodayDate(symbol) {         symbol = symbol || '-';         var nowDate = new Date(),             year = nowDate.getFullYear(),             month = nowDate.getMonth() + 1,             day = nowDate.getDate();         month = month < 10 ? '0' + month : month;         day = day < 10 ? '0' + day : day;         return year + symbol + month + symbol + day;     }    getTodayDate('-')  //結果:2016-11-26

2.獲取之前N月(n<0)或者之後N月(n>0)

function getAnyMonth(symbol,n) {


  symbol = symbol||'-';
  var nowDate = new Date();
  nowDate.setMonth(nowDate.getMonth()+n);
  var year = nowDate.getFullYear(),
      month = nowDate.getMonth()+1;
  month = month < 10 ? '0' + month : month;
  return year + symbol + month;
}獲取現在之前兩個月：getAnyMonth('', -2) //結果：2016-09

3.獲取之前N天(n<0)或者之後N天(n>0)

    function getAnyDay(symbol, n) {         symbol = symbol || '-';         var nowDate = new Date();         nowDate = nowDate.setDate(nowDate.getDate() + n);         nowDate = new Date(nowDate);         var y = nowDate.getFullYear(),             m = nowDate.getMonth() + 1,             d = nowDate.getDate();         m = m < 10 ? '0' + m : m;         d = d < 10 ? '0' + d : d;         return y + symbol + m + symbol + d;     }
    獲取現在之前5天：getAnyDay('-', -5) //結果：2016-11-21

4. 獲取之前N小時(n<0)或者之後N小時(n>0)

    function getAnyHour(symbol, n) {        symbol = symbol || '-';         var nowDate = new Date();         nowDate = nowDate.setHours(nowDate.getHours() + n);         nowDate = new Date(nowDate);         vary = nowDate.getFullYear(),             m = nowDate.getMonth() + 1,             d = nowDate.getDate(),             h = nowDate.getHours(),             mi = nowDate.getMinutes();         m = m < 10 ? '0' + m : m;         d = d < 10 ? '0' + d : d;         h = h < 10 ? '0' + h : h;         mi = mi < 10 ? '0' + mi : mi;         return y + symbol + m + symbol + d + ' ' + h + ':' + mi;     }     獲取現在之前5小時：getAnyHour('-', -5) //結果：2016-11-26 06:15