使用JavaScript從今天起計算過去日期

Question

下面的JavaScript對象有一些過去的日期值設置。我需要使用JavaScript從當前日期計算這些值。

眼下的日期值手動設置，但他們應該會自動使用JavaScript

計算

例如，對於Last Week日期應以當前周的開始日期之前使用該日爲end date爲Last Week然後在6天前計算得到start date的Last Week。

如何在JS中執行此操作並在所有瀏覽器中工作？

我很好用MomentJS是對這種類型的事情有用嗎？

// Date Divider Date values for cocomparisoagainstt Tasks created_at DateTime 
var dateRangeLabels = { 
    'Today': { 
     'start': new Date('2015-09-12T00:00:00'), 
     'end': new Date('2015-09-12T00:00:00'), 
     'dateFunc': 'inRange' 
    }, 
    'Yesterday': { 
     'start': new Date('2015-09-11T00:00:00'), 
     'end': new Date('2015-09-11T00:00:00'), 
     'dateFunc': 'inRange' 
    }, 
    'Earlier this Week': { 
     'start': new Date('2015-09-06T00:00:00'), 
     'end': new Date('2015-09-10T00:00:00'), 
     'dateFunc': 'inRange' 
    }, 
    'Last Week': { 
     'start': new Date('2015-08-30T00:00:00'), 
     'end': new Date('2015-09-05T00:00:00'), 
     'dateFunc': 'inRange' 
    }, 
    'A while Ago': { 
     'start': new Date('2010-08-30T00:00:00'), 
     'end': new Date('2015-07-31T00:00:00'), 
     'dateFunc': 'inRange' 
    }, 
    'Last Month': { 
     'start': new Date('2015-08-01T00:00:00'), 
     'end': new Date('2015-08-31T00:00:00'), 
     'dateFunc': 'inRange' 
    }, 
    'Earliar in the Month': { 
     'start': new Date('2015-08-30T00:00:00'), 
     'end': new Date('2015-09-05T00:00:00'), 
     'dateFunc': 'inRange' 
    }, 
    'other': { 
     'start': new Date('2015-09-13T00:00:00'), 
     'end': new Date('2999-12-31T00:00:00'), 
     'dateFunc': 'inRange' 
    } 
} 

---

該日曆圖像的可視化和start日期end我需要得到基於命名的持續時間值。

對於last week我需要確定上週從今天開始的start和end的日期。在這個例子是：
start date: 1/4/2016和end date: 1/10/2016

Answer 1

如果我理解正確..這應該做的伎倆。

$(function() { 
 
      convertDays = function (d) { 
 
       //Convert days into MilliSeconds 
 
       return d * 86400000; 
 
      } 
 

 
      var today = new Date(); 
 
      var dateRangeLabels = { 
 
       Today: { 
 
        start: today, 
 
        end: today, 
 
        dateFunc: 'inRange' 
 
       }, 
 
       Yesterday: { 
 
        start: new Date(today - convertDays(1)), 
 
        end: today, 
 
        dateFunc: 'inRange' 
 
       }, 
 
       WeekAgo: { 
 
        start: new Date(today - convertDays(7)), 
 
        end: today, 
 
        dateFunc: 'inRange' 
 
       } 
 
      }; 
 

 
      console.log(dateRangeLabels); 
 

 
     });

編輯：包括數週和數月的第一&最後一天。這當然可以按照您的喜好縮放。

$(function() { 
 
      convertDays = function (d) { 
 
       //Convert days into MilliSeconds 
 
       return d * 86400000; 
 
      } 
 
      fDayofWeek = function (d) { 
 
       return new Date(d - convertDays(d.getDay())); 
 
      } 
 
      lDayofWeek = function (d) { 
 
       return new Date((d - convertDays(d.getDay())) + convertDays(6)); 
 
      } 
 
      fDayofMonth = function (d) { 
 
       return new Date(d.getFullYear(), d.getMonth(), 1); 
 
      } 
 
      lDayofMonth = function (d) { 
 
       return new Date(d.getFullYear(), d.getMonth() + 1, 0); 
 
      } 
 

 
      var today = new Date(); 
 
      var dateRangeLabels = { 
 
       Today: { 
 
        start: today, 
 
        end: today, 
 
        dateFunc: 'inRange' 
 
       }, 
 
       Yesterday: { 
 
        start: new Date(today - convertDays(1)), 
 
        end: today, 
 
        dateFunc: 'inRange' 
 
       }, 
 
       WeekAgo: { 
 
        start: new Date(today - convertDays(7)), 
 
        end: today, 
 
        dateFunc: 'inRange' 
 
       }, 
 
       ThisWeek: { 
 
        start: fDayofWeek(today), //Sunday 
 
        end: lDayofWeek(today) //Saturday 
 
       }, 
 
       ThisMonth: { 
 
        start: fDayofMonth(today), 
 
        end: lDayofMonth(today) 
 
       } 
 
      }; 
 

 
      console.log(dateRangeLabels); 
 

 
     });

Answer 2

它不會是太難手動計算它沒有一個圖書館。剛做這樣的事情：

function sq(num) { 
    return num * num; 
} 
var times = { 
    "min": 60, 
    "hour": sq(60), 
    "day": (sq(60) * 24), 
    "week": (sq(60) * 24 * 7), 
    "month": (sq(60) * 24 * 7 * 4), 
    "year": (sq(60) * 24 * 7 * 4 * 12) 
}; 
return function(date, max) { 
    if (!date) return ""; 
    var d = new Date(date), 
    diff = ((Date.now() - d.getTime())/1000); 
    if (diff < times.min) { 
    return "now"; 
    } else if (diff < times.hour) { 
    return Math.floor(diff/times.min) + " min ago"; 
    } else if (diff < times.day) { 
    return Math.floor(diff/times.hour) + " hours ago"; 
    } else if (diff < times.week) { 
    return Math.floor(diff/times.day) + " days ago"; 
    } else if (diff < times.month) { 
    return Math.floor(diff/times.week) + " weeks ago"; 
    } else if (diff < times.year) { 
    return Math.floor(diff/times.month) + " months ago"; 
    } //else over a year 
    return "over a year ago"; 
}; 

您可以使用Date.getDay（）來獲得按照本地時間(returns 0-6)的一週的開始，並相應地調整上面。