[C#] DateTime 형 유용한 유틸 라이브러리

namespace DateTimeLibrary

{

using System;

using System.Collections;

public class DateTimeLibrary

{

public static string FirstDayOfCurrentMonth()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month, 1);

return time2.ToShortDateString();

}

public static string FirstDayOfCurrenttQuarter()

{

DateTime time2;

DateTime time3;

DateTime today = DateTime.Today;

int num = int.Parse(today.Month.ToString());

if (num != 0)

{

int num2 = (num % 3) - 1;

time3 = today.AddMonths(-num2);

time2 = new DateTime(time3.Year, time3.Month, 1);

}

else

{

time3 = today.AddMonths(-2);

time2 = new DateTime(time3.Year, time3.Month, 1);

}

return time2.ToShortDateString();

}

public static string FirstDayOfCurrenttWeek()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month, today.Day);

Hashtable hashtable = new Hashtable();

hashtable["Monday"] = "0";

hashtable["Tuesday"] = "1";

hashtable["Wednesday"] = "2";

hashtable["Thursday"] = "3";

hashtable["Friday"] = "4";

hashtable["Saturday"] = "5";

hashtable["Sunday"] = "6";

string s = (string) hashtable[today.DayOfWeek.ToString()];

int num = int.Parse(s);

return time2.AddDays((double) -num).ToShortDateString();

}

public static string FirstDayOfCurrentYear()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, 1, 1);

return time2.ToShortDateString();

}

public static string FirstDayOfLastMonth()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month - 1, 1);

return time2.ToShortDateString();

}

public static string FirstDayOfLastQuarter()

{

DateTime time2;

DateTime time3;

DateTime today = DateTime.Today;

int num = int.Parse(today.Month.ToString());

if (num != 0)

{

int num2 = (num % 3) - 1;

time3 = today.AddMonths(-(num2 + 3));

time2 = new DateTime(time3.Year, time3.Month, 1);

}

else

{

time3 = today.AddMonths(-5);

time2 = new DateTime(time3.Year, time3.Month, 1);

}

return time2.ToShortDateString();

}

public static string FirstDayOfLastWeek()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month, today.Day);

Hashtable hashtable = new Hashtable();

hashtable["Monday"] = "0";

hashtable["Tuesday"] = "1";

hashtable["Wednesday"] = "2";

hashtable["Thursday"] = "3";

hashtable["Friday"] = "4";

hashtable["Saturday"] = "5";

hashtable["Sunday"] = "6";

string s = (string) hashtable[today.DayOfWeek.ToString()];

int num = int.Parse(s) + 7;

return time2.AddDays((double) -num).ToShortDateString();

}

public static string FirstDayOfLastYear()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year - 1, 1, 1);

return time2.ToShortDateString();

}

public static string FirstDayOfNextMonth()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month + 1, 1);

return time2.ToShortDateString();

}

public static string FirstDayOfNextQuarter()

{

DateTime time3;

DateTime today = DateTime.Today;

int num = int.Parse(today.Month.ToString());

if (num != 0)

{

int month = num + (3 - (num % 3));

DateTime time2 = new DateTime(today.Year, month, 1);

time3 = time2.AddMonths(1);

}

else

{

time3 = new DateTime(today.Year, today.Month, 1).AddMonths(1);

}

return time3.ToShortDateString();

}

public static string FirstDayOfNextWeek()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month, today.Day);

Hashtable hashtable = new Hashtable();

hashtable["Monday"] = "0";

hashtable["Tuesday"] = "1";

hashtable["Wednesday"] = "2";

hashtable["Thursday"] = "3";

hashtable["Friday"] = "4";

hashtable["Saturday"] = "5";

hashtable["Sunday"] = "6";

string s = (string) hashtable[today.DayOfWeek.ToString()];

int num = int.Parse(s);

return time2.AddDays((double) (-num + 7)).ToShortDateString();

}

public static string FirstDayOfNextYear()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year + 1, 1, 1);

return time2.ToShortDateString();

}

public static string LastDayOfCurrentMonth()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month + 1, 1);

return time2.AddDays(-1.0).ToShortDateString();

}

public static string LastDayOfCurrenttQuarter()

{

DateTime time2;

DateTime time3;

DateTime today = DateTime.Today;

int num = int.Parse(today.Month.ToString());

if (num != 0)

{

int month = num + (3 - (num % 3));

time2 = new DateTime(today.Year, month, 1);

time2.AddMonths(1);

time2.AddDays(-1.0);

time3 = time2.AddMonths(1).AddDays(-1.0);

}

else

{

time2 = new DateTime(today.Year, today.Month, 1);

time2.AddMonths(1);

time2.AddDays(-1.0);

time3 = time2.AddMonths(1).AddDays(-1.0);

}

return time3.ToShortDateString();

}

public static string LastDayOfCurrentWeek()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month, today.Day);

Hashtable hashtable = new Hashtable();

hashtable["Monday"] = "0";

hashtable["Tuesday"] = "1";

hashtable["Wednesday"] = "2";

hashtable["Thursday"] = "3";

hashtable["Friday"] = "4";

hashtable["Saturday"] = "5";

hashtable["Sunday"] = "6";

string s = (string) hashtable[today.DayOfWeek.ToString()];

int num = int.Parse(s) + 1;

return time2.AddDays((double) (-num + 7)).ToShortDateString();

}

public static string LastDayOfCurrentYear()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, 12, 0x1f);

return time2.ToShortDateString();

}

public static string LastDayOfLastMonth()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month - 1, 1);

return time2.AddMonths(1).AddDays(-1.0).ToShortDateString();

}

public static string LastDayOfLastQuarter()

{

DateTime time2;

DateTime time3;

DateTime today = DateTime.Today;

int num = int.Parse(today.Month.ToString());

if (num != 0)

{

int month = num + (3 - (num % 3));

time2 = new DateTime(today.Year, month, 1);

time3 = time2.AddMonths(1).AddDays(-1.0).AddMonths(-3);

}

else

{

time2 = new DateTime(today.Year, today.Month, 1);

time3 = time2.AddMonths(1).AddDays(-1.0).AddMonths(-3);

}

return time3.ToShortDateString();

}

public static string LastDayOfLastYear()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year - 1, 12, 0x1f);

return time2.ToShortDateString();

}

public static string LastDayOfNextMonth()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month + 2, 1);

return time2.AddDays(-1.0).ToShortDateString();

}

public static string LastDayOfNextQuarter()

{

DateTime time2;

DateTime time3;

DateTime today = DateTime.Today;

int num = int.Parse(today.Month.ToString());

if (num != 0)

{

int month = num + (3 - (num % 3));

time2 = new DateTime(today.Year, month, 1);

time3 = time2.AddMonths(1).AddMonths(3).AddDays(-1.0);

}

else

{

time2 = new DateTime(today.Year, today.Month, 1);

time3 = time2.AddMonths(1).AddMonths(3).AddDays(-1.0);

}

return time3.ToShortDateString();

}

public static string LastDayOfNextWeek()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month, today.Day);

Hashtable hashtable = new Hashtable();

hashtable["Monday"] = "0";

hashtable["Tuesday"] = "1";

hashtable["Wednesday"] = "2";

hashtable["Thursday"] = "3";

hashtable["Friday"] = "4";

hashtable["Saturday"] = "5";

hashtable["Sunday"] = "6";

string s = (string) hashtable[today.DayOfWeek.ToString()];

int num = int.Parse(s) + 1;

return time2.AddDays((double) (-num + 14)).ToShortDateString();

}

public static string LastDayOfNextYear()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year + 1, 12, 0x1f);

return time2.ToShortDateString();

}

public static string LastOfLastWeek()

{

DateTime today = DateTime.Today;

DateTime time2 = new DateTime(today.Year, today.Month, today.Day);

Hashtable hashtable = new Hashtable();

hashtable["Monday"] = "0";

hashtable["Tuesday"] = "1";

hashtable["Wednesday"] = "2";

hashtable["Thursday"] = "3";

hashtable["Friday"] = "4";

hashtable["Saturday"] = "5";

hashtable["Sunday"] = "6";

string s = (string) hashtable[today.DayOfWeek.ToString()];

int num = int.Parse(s) + 1;

return time2.AddDays((double) -num).ToShortDateString();

}

}

}