如何在 Javascript 中过去 7 天和下一个 7 天

Question

我正在尝试使用 javascript 日期函数获取过去 7 天和接下来 7 天的日期开始数据和结束日期。

例如：今天 2017 年 3 月 31 日，当我单击上一个按钮时，它将从上一个日期开始计算，即：开始和结束日期，（2017 年 3 月 24 日至 2017 年 3 月 30 日），再次单击上一个（2017 年 3 月 17 日至 3 月 23 日） 2017）等等。

下一个按钮也会复制同样的东西..

我尝试了以下方法，但它不起作用

 function getPreviousWeek(){
      ProHistoryCtrl.weekPrevcount = ProHistoryCtrl.weekPrevcount + 1;
      ProHistoryCtrl.weekPrevious  = (-6 * ProHistoryCtrl.weekPrevcount);
      getByWeek();
}

 function getNextWeek(){
      ProHistoryCtrl.weekPrevcount = ProHistoryCtrl.weekPrevcount - 1;
      ProHistoryCtrl.weekPrevious  = (-6 * ProHistoryCtrl.weekPrevcount);
      getByWeek();
}


function getByWeek(){   

      console.log("weekpreviouscount" + ProHistoryCtrl.weekPrevcount); //-6,-12,-18,-24
      console.log("weekprevious" + ProHistoryCtrl.weekPrevious); //-6,-12,-18,-24
      var d2 = new Date(); // 31.01.2017
      var d1 = new Date(d2);
      d1.setDate(d2.getDate() - 1); // 30.01.2017
      var previousWeek = '';
      var current_day = '';

      console.log("d2date" + d1.getDate());
      console.log("week2" + ProHistoryCtrl.weekPrevious)
      previousWeek = new Date(d1);
      previousWeek.setDate(d1.getDate() + ProHistoryCtrl.weekPrevious); // 30-13=17

      current_day = new Date(d1); // 30.01.2017
      current_day.setDate(d1.getDate() + ProHistoryCtrl.weekPrevious + 6); // 30-12+5=23

      console.log("currentdayprevious" + ProHistoryCtrl.weekPrevious); //-6,-12,-18,-24

      var previousWeekUTCTimestamp = Math.floor(previousWeek.getTime() / 1000);
      var currentUTC = Math.floor(current_day.getTime() / 1000);

      console.log("previousWeekUTCTimestamp" + previousWeekUTCTimestamp);
      console.log("currentUTC" + currentUTC);

      var sinceUTC = previousWeekUTCTimestamp;
      var untilUTC = currentUTC;

}

第一次正确的时间是 2017 年 3 月 24 日到 2017 年 3 月 30 日，下一次是 2017 年 3 月 24 日到 18 日

有什么想法吗？请

Answer 1

问题似乎出在你的数学上，你可以通过每周减去 6 然后再减去额外的 1 来获得前一周。这对于 -6 -1 = -7 的第一周很好，但是对于第二周周这是 (-6 * 2) - 1 = -13 但两周应该是 -14。不正确的代码是：

ProHistoryCtrl.weekPrevious  = (-6 * ProHistoryCtrl.weekPrevcount);

d1.setDate(d2.getDate() - 1);

因此，解决方案是：

 function getPreviousWeek(){
            ProHistoryCtrl.weekPrevcount = ProHistoryCtrl.weekPrevcount + 1;
            ProHistoryCtrl.weekPrevious  = (-7 * ProHistoryCtrl.weekPrevcount);
            getByWeek();
}

 function getNextWeek(){
            ProHistoryCtrl.weekPrevcount = ProHistoryCtrl.weekPrevcount - 1;
            ProHistoryCtrl.weekPrevious  = (-7 * ProHistoryCtrl.weekPrevcount);
            getByWeek();
}

function getByWeek(){   

    var d2 = new Date(); // 31.01.2017
    var d1 = new Date(d2);
    d1.setDate(d2.getDate()); // 30.01.2017
    var previousWeek = '';
    var current_day = '';

    previousWeek = new Date(d1);
    previousWeek.setDate(d1.getDate() + ProHistoryCtrl.weekPrevious); // 30-13=17

    current_day = new Date(d1); // 30.01.2017
    current_day.setDate(d1.getDate() + ProHistoryCtrl.weekPrevious + 6); // 30-12+5=23

    var previousWeekUTCTimestamp = Math.floor(previousWeek.getTime() / 1000);
    var currentUTC = Math.floor(current_day.getTime() / 1000);

    var sinceUTC = previousWeekUTCTimestamp;
    var untilUTC = currentUTC;
}

Answer 2

使用此功能。你不需要额外的功能

var btn = document.querySelector("button")

Date.prototype.addDays = function(days) {
  this.setDate(this.getDate() + parseInt(days));
  return this;
};


function getDate(days) {
  var date = new Date().addDays(days);
  return date
}



btn.addEventListener("click", function() {
  var pastSevenDays = getDate(-7)
  var nextSevenDays = getDate(7)
  // only date
  console.log(pastSevenDays.toLocaleString().slice(0,10))
  console.log(nextSevenDays.toLocaleString().slice(0,10))
}, false)

<button>Get Dates</button>