c# - 获取具体日期

Question

我正在使用 C# 中的日期，需要计算一些进一步的日期。以当前datetime.

如何获得以下值？

• 一天的结束
• 月底
• 年底

Answer 1

如果end of ...你的意思是12:59:59.999PM在那一天，那么：

• 一天的结束

  var today = DateTime.Today;
  var endOfDay = new DateTime(
      today.Year, 
      today.Month,
      today.Day,
      23,
      59,
      59,
      999
  );
  

• 月底

  var today = DateTime.Today;
  var endOfMonth = new DateTime(
      today.Year, 
      today.Month,
      DateTime.DaysInMonth(today.Year, today.Month),
      23,
      59,
      59,
      999
  );
  

• 年底

  var today = DateTime.Today;
  var endOfYear = new DateTime(
      today.Year,
      12,
      31,
      23,
      59,
      59,
      999
  );
  

如果你的意思是别的，然后解释你的意思。

Answer 2

对于月底

DateTime today = DateTime.Today;
DateTime endOfMonth = new DateTime(today.Year, today.Month, DateTime.DaysInMonth(today.Year, today.Month));

请参阅如何在 C# 中获取月份的最后一天？

到年底

DateTime endOfYear = new DateTime(today.Year, 12, 31);

对于一天结束，假设一天结束是下午 5 点下班

DateTime endOfDay = new DateTime(today.Year, today.Month, today.day, 17, 0, 0); // Assuming the business end of day is at 5 PM

在http://msdn.microsoft.com/en-us/library/system.datetime.aspx上查看有关日期时间的更多信息

Answer 3

一个月的最后一天：

DateTime today = DateTime.Now;
DateTime lastDayOfMonth = new DateTime(today.Year, today.Month, DateTime.DaysInMonth(today.Year, today.Month));

一年中的最后一天：

DateTime today = DateTime.Now;
DateTime lastDayOfYear = new DateTime(today.Year, 12, 31);