2016-09-30 97 views
2

我需要获取两个日期之间的星期数。
对我来说一星期是星期一到星期日。
所以如果第一个日期是在本周的星期六应该包括在内。
如果第二个日期是比本周一个星期一应该包括在内。包含两个日期之间的星期数

什么是最有效的方法来做到这一点?

例如:

startdate enddate  nbr of weeks 
17/09/2016 26/09/2016 3 weeks 
17/09/2016 25/09/2016 2 weeks 
19/09/2016 26/09/2016 2 weeks 
12/09/2016 25/09/2016 2 weeks 

我找到了这么多答案,像这样的例如how to calculate number of weeks given 2 dates?但他们都最终与分割天7,并且不给出结果,我需要。

+0

@Roy_Dorsthorst:我看不出这将是部分解。这只是格式化 - 它与计算日期之间的差异无关。 –

回答

5

最简单的方法可能是编写一个方法来获得一周的开始。然后你可以从另一个日期中减去一个日期,将天数除以7并加1(使之包含在内)。

个人而言,我会使用Noda Time所有这一切,但使用DateTime

// Always uses Monday-to-Sunday weeks 
public static DateTime GetStartOfWeek(DateTime input) 
{ 
    // Using +6 here leaves Monday as 0, Tuesday as 1 etc. 
    int dayOfWeek = (((int) input.DayOfWeek) + 6) % 7; 
    return input.Date.AddDays(-dayOfWeek); 
} 

public static int GetWeeks(DateTime start, DateTime end) 
{ 
    start = GetStartOfWeek(start); 
    end = GetStartOfWeek(end); 
    int days = (int) (end - start).TotalDays; 
    return (days/7) + 1; // Adding 1 to be inclusive 
} 

完整的示例:

using System; 

class Program 
{ 
    static void Main (string[] args) 
    { 
     ShowWeeks(new DateTime(2016, 9, 17), new DateTime(2016, 9, 26)); 
     ShowWeeks(new DateTime(2016, 9, 17), new DateTime(2016, 9, 25)); 
     ShowWeeks(new DateTime(2016, 9, 19), new DateTime(2016, 9, 26)); 
     ShowWeeks(new DateTime(2016, 9, 12), new DateTime(2016, 9, 25)); 
    } 

    static void ShowWeeks(DateTime start, DateTime end) 
    { 
     int weeks = GetWeeks(start, end); 
     Console.WriteLine($"{start:d} {end:d} {weeks}"); 
    } 

    // Always uses Monday-to-Sunday weeks 
    public static DateTime GetStartOfWeek(DateTime input) 
    { 
     // Using +6 here leaves Monday as 0, Tuesday as 1 etc. 
     int dayOfWeek = (((int) input.DayOfWeek) + 6) % 7; 
     return input.Date.AddDays(-dayOfWeek); 
    } 

    public static int GetWeeks(DateTime start, DateTime end) 
    { 
     start = GetStartOfWeek(start); 
     end = GetStartOfWeek(end); 
     int days = (int) (end - start).TotalDays; 
     return (days/7) + 1; // Adding 1 to be inclusive 
    } 
} 

输出(在我的英国语言环境):

17/09/2016 26/09/2016 3 
17/09/2016 25/09/2016 2 
19/09/2016 26/09/2016 2 
12/09/2016 25/09/2016 2 
+1

'GetEndOfWeek'是一个错字,或者你省略了一个方法。 – Abion47

+0

@ Abion47:错字 - 现在修复。 –

3

看到我下面的方法,我“星期天”到星期一,直到星期日,然后计算总天数/ 7

public static void Main(string[] args) 
    { 
     Console.WriteLine(CalculateWeeks(new DateTime(2016, 9, 17), new DateTime(2016, 9, 26))); 
     Console.WriteLine(CalculateWeeks(new DateTime(2016, 9, 17), new DateTime(2016, 9, 25))); 
     Console.WriteLine(CalculateWeeks(new DateTime(2016, 9, 19), new DateTime(2016, 9, 26))); 
     Console.WriteLine(CalculateWeeks(new DateTime(2016, 9, 12), new DateTime(2016, 9, 25))); 

    } 

    public static double CalculateWeeks(DateTime from, DateTime to) 
    { 
     if (to.DayOfWeek != DayOfWeek.Sunday) 
      to = to.Add(new TimeSpan(7- (int) to.DayOfWeek, 0, 0, 0)).Date; 
     return Math.Ceiling((to - from.Subtract(new TimeSpan((int)from.DayOfWeek - 1, 0, 0, 0)).Date).TotalDays/7); 
    } 
2

有点“简化”,因为需要只是开始日期的星期一:

static int weeks(DateTime d1, DateTime d2) { 
    var daysSinceMonday = ((int)d1.DayOfWeek + 6) % 7; 
    return ((d2 - d1).Days + daysSinceMonday)/7 + 1; 
} 
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