发一个专门处理时间和日期的类库，记录以备查询。
using System;
namespace Utilities
{
/// <summary>
/// Common DateTime Methods.
/// </summary>
///
public enum Quarter
{
First = 1,
Second = 2,
Third = 3,
Fourth = 4
}
public enum Month
{
January = 1,
February = 2,
March = 3,
April = 4,
May = 5,
June = 6,
July = 7,
August = 8,
September = 9,
October = 10,
November = 11,
December = 12
}
public class DateUtilities
{
#region Quarter
public static DateTime GetStartOfQuarter( int Year, Quarter Qtr )
{
if( Qtr == Quarter.First ) // 1st Quarter = January 1 to March 31
return new DateTime( Year, 1, 1, 0, 0, 0, 0 );
else if( Qtr == Quarter.Second ) // 2nd Quarter = April 1 to June 30
return new DateTime( Year, 4, 1, 0, 0, 0, 0 );
else if( Qtr == Quarter.Third ) // 3rd Quarter = July 1 to September 30
return new DateTime( Year, 7, 1, 0, 0, 0, 0 );
else // 4th Quarter = October 1 to December 31
return new DateTime( Year, 10, 1, 0, 0, 0, 0 );
}
public static DateTime GetEndOfQuarter( int Year, Quarter Qtr )
{
if( Qtr == Quarter.First ) // 1st Quarter = January 1 to March 31
return new DateTime( Year, 3, DateTime.DaysInMonth( Year, 3 ), 23, 59, 59, 999 );
else if( Qtr == Quarter.Second ) // 2nd Quarter = April 1 to June 30
return new DateTime( Year, 6, DateTime.DaysInMonth( Year, 6 ), 23, 59, 59, 999 );
else if( Qtr == Quarter.Third ) // 3rd Quarter = July 1 to September 30
return new DateTime( Year, 9, DateTime.DaysInMonth( Year, 9 ), 23, 59, 59, 999 );
else // 4th Quarter = October 1 to December 31
return new DateTime( Year, 12, DateTime.DaysInMonth( Year, 12 ), 23, 59, 59, 999 );
}
public static Quarter GetQuarter( Month month )
{
if( month <= Month.March ) // 1st Quarter = January 1 to March 31
return Quarter.First;
else if( ( month >= Month.April ) && ( month <= Month.June ) ) // 2nd Quarter = April 1 to June 30
return Quarter.Second;
else if( ( month >= Month.July ) && ( month <= Month.September ) ) // 3rd Quarter = July 1 to September 30
return Quarter.Third;
else // 4th Quarter = October 1 to December 31
return Quarter.Fourth;
}
public static DateTime GetEndOfLastQuarter()
{
if( DateTime.Now.Month <= (int)Month.March ) //go to last quarter of previous year
return GetEndOfQuarter( DateTime.Now.Year - 1, GetQuarter( Month.December ));
else //return last quarter of current year
return GetEndOfQuarter( DateTime.Now.Year, GetQuarter( (Month)DateTime.Now.Month));
}
public static DateTime GetStartOfLastQuarter()
{
if( DateTime.Now.Month <= 3 ) //go to last quarter of previous year
return GetStartOfQuarter( DateTime.Now.Year - 1, GetQuarter( Month.December ));
else //return last quarter of current year
return GetStartOfQuarter( DateTime.Now.Year, GetQuarter( (Month)DateTime.Now.Month));
}
public static DateTime GetStartOfCurrentQuarter()
{
return GetStartOfQuarter( DateTime.Now.Year, GetQuarter( (Month)DateTime.Now.Month ));
}
public static DateTime GetEndOfCurrentQuarter()
{
return GetEndOfQuarter( DateTime.Now.Year, GetQuarter( (Month)DateTime.Now.Month ));
}
#endregion
#region Weeks
public static DateTime GetStartOfLastWeek()
{
int DaysToSubtract = (int)DateTime.Now.DayOfWeek + 7;
DateTime dt = DateTime.Now.Subtract( System.TimeSpan.FromDays( DaysToSubtract ) );
return new DateTime( dt.Year, dt.Month, dt.Day, 0, 0, 0, 0 );
}
public static DateTime GetEndOfLastWeek()
{
DateTime dt = GetStartOfLastWeek().AddDays(6);
return new DateTime( dt.Year, dt.Month, dt.Day, 23, 59, 59, 999 );
}
public static DateTime GetStartOfCurrentWeek()
{
int DaysToSubtract = (int)DateTime.Now.DayOfWeek ;
DateTime dt = DateTime.Now.Subtract( System.TimeSpan.FromDays( DaysToSubtract ) );
return new DateTime( dt.Year, dt.Month, dt.Day, 0, 0, 0, 0 );
}
public static DateTime GetEndOfCurrentWeek()
{
DateTime dt = GetStartOfCurrentWeek().AddDays(6);
return new DateTime( dt.Year, dt.Month, dt.Day, 23, 59, 59, 999 );
}
#endregion
#region Months
public static DateTime GetStartOfMonth( int Month, int Year )
{
return new DateTime( Year, Month, 1, 0, 0, 0, 0 );
}
public static DateTime GetEndOfMonth( int Month, int Year )
{
return new DateTime( Year, Month, DateTime.DaysInMonth( Year, Month ), 23, 59, 59, 999 );
}
public static DateTime GetStartOfLastMonth()
{
if( DateTime.Now.Month == 1 )
return GetStartOfMonth( 12, DateTime.Now.Year - 1);
else
return GetStartOfMonth( DateTime.Now.Month -1, DateTime.Now.Year );
}
public static DateTime GetEndOfLastMonth()
{
if( DateTime.Now.Month == 1 )
return GetEndOfMonth( 12, DateTime.Now.Year - 1);
else
return GetEndOfMonth( DateTime.Now.Month -1, DateTime.Now.Year );
}
public static DateTime GetStartOfCurrentMonth()
{
return GetStartOfMonth( DateTime.Now.Month, DateTime.Now.Year );
}
public static DateTime GetEndOfCurrentMonth()
{
return GetEndOfMonth( DateTime.Now.Month, DateTime.Now.Year );
}
#endregion
#region Years
public static DateTime GetStartOfYear( int Year )
{
return new DateTime( Year, 1, 1, 0, 0, 0, 0 );
}
public static DateTime GetEndOfYear( int Year )
{
return new DateTime( Year, 12, DateTime.DaysInMonth( Year, 12 ), 23, 59, 59, 999 );
}
public static DateTime GetStartOfLastYear()
{
return GetStartOfYear( DateTime.Now.Year - 1 );
}
public static DateTime GetEndOfLastYear()
{
return GetEndOfYear( DateTime.Now.Year - 1 );
}
public static DateTime GetStartOfCurrentYear()
{
return GetStartOfYear( DateTime.Now.Year );
}
public static DateTime GetEndOfCurrentYear()
{
return GetEndOfYear( DateTime.Now.Year );
}
#endregion
#region Days
public static DateTime GetStartOfDay( DateTime date )
{
return new DateTime( date.Year, date.Month, date.Day, 0, 0, 0, 0 );
}
public static DateTime GetEndOfDay( DateTime date )
{
return new DateTime( date.Year, date.Month, date.Day, 23, 59, 59, 999 );
}
#endregion
}
}
本文转自Jaxu博客园博客，原文链接：http://www.cnblogs.com/jaxu/archive/2011/12/31/2308376.html，如需转载请自行联系原作者
