asp.net下日期和时间处理的类库

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
}
}