C # Format and usage of the current time given by datetime

DateTime.Now.ToShortTimeString ()
DateTime dt = DateTime.Now;
Dt. ToString ();//2005-11-5 13:21:25
Dt. Tofiletime (). ToString ();//127756416859912816
Dt. TOFILETIMEUTC (). ToString ();//127756704859912816
Dt. ToLocalTime (). ToString ();//2005-11-5 21:21:25
Dt. Tolongdatestring (). ToString ();//November 5, 2005
Dt. Tolongtimestring (). ToString ();//13:21:25
Dt. ToOADate (). ToString ();//38661.5565508218
Dt. ToShortDateString (). ToString ();//2005-11-5
Dt. Toshorttimestring (). ToString ();//13:21
Dt. ToUniversalTime (). ToString ();//2005-11-5 5:21:25
Dt. Year.tostring ();//2005
Dt. Date.tostring ();//2005-11-5 0:00:00
Dt. Dayofweek.tostring ();//saturday
Dt. Dayofyear.tostring ();//309
Dt. Hour.tostring ();//13
Dt.Millisecond.ToString ();//441
Dt. Minute.tostring ();//30
Dt. Month.tostring ();//11
Dt. Second.tostring ();//28
Dt. Ticks.tostring ();//632667942284412864
Dt. Timeofday.tostring ();//13:30:28.4412864
Dt. ToString ();//2005-11-5 13:47:04
Dt. AddYears (1). ToString ();//2006-11-5 13:47:04
Dt. AddDays (1.1). ToString ();//2005-11-6 16:11:04
Dt. AddHours (1.1). ToString ();//2005-11-5 14:53:04
Dt. Addmilliseconds (1.1). ToString ();//2005-11-5 13:47:04
Dt. AddMonths (1). ToString ();//2005-12-5 13:47:04
Dt. AddSeconds (1.1). ToString ();//2005-11-5 13:47:05
Dt. AddMinutes (1.1). ToString ();//2005-11-5 13:48:10
Dt. Addticks (1000). ToString ();//2005-11-5 13:47:04
Dt.compareto (DT). ToString ();//0
Dt. ADD (?). ToString ();//question mark is a time period
Dt. Equals ("2005-11-6 16:11:04"). ToString ();//false
Dt. Equals (DT). ToString ();//true
Dt. GetHashCode (). ToString ();//1474088234
Dt. GetType (). ToString ();//system.datetime
Dt. GetTypeCode (). ToString ();//datetime

Dt. Getdatetimeformats (' s ') [0]. ToString ();//2005-11-05t14:06:25
Dt. Getdatetimeformats (' t ') [0]. ToString ();//14:06
Dt. Getdatetimeformats (' y ') [0]. ToString ();//November 2005
Dt. Getdatetimeformats (' D ') [0]. ToString ();//November 5, 2005
Dt. Getdatetimeformats (' D ') [1]. ToString ();//2005 11 05
Dt. Getdatetimeformats (' D ') [2]. ToString ();//Saturday 2005 11 05
Dt. Getdatetimeformats (' D ') [3]. ToString ();//Saturday November 5, 2005
Dt. Getdatetimeformats (' M ') [0]. ToString ();//November 5
Dt. Getdatetimeformats (' f ') [0]. ToString ();//November 5, 2005 14:06
Dt. Getdatetimeformats (' g ') [0]. ToString ();//2005-11-5 14:06
Dt. Getdatetimeformats (' R ') [0]. ToString ();//sat, 2005 14:06:25 GMT
String. Format ("{0:d}", DT);//2005-11-5
String. Format ("{0}", dt);//November 5, 2005
String. Format ("{0:f}", dt);//November 5, 2005 14:23
String. Format ("{0:f}", dt);//November 5, 2005 14:23:23
String. Format ("{0:g}", DT);//2005-11-5 14:23
String. Format ("{0:g}", DT);//2005-11-5 14:23:23
String. Format ("{0:m}", dt);//November 5
String. Format ("{0:r}", DT);//sat, 2005 14:23:23 GMT
String. Format ("{0:s}", DT);//2005-11-05t14:23:23
String. Format ("{0:t}", DT);//14:23
String. Format ("{0:t}", DT);//14:23:23
String. Format ("{0:u}", DT);//2005-11-05 14:23:23z
String. Format ("{0:u}", dt);//November 5, 2005 6:23:23
String. Format ("{0:y}", dt);//November 2005
String. Format ("{0}", dt);//2005-11-5 14:23:23
String. Format ("{0:yyyymmddhhmmssffff}", DT);
Calculates the difference in the number of days between 2 dates
-----------------------------------------------
DateTime dt1 = Convert.datetime ("2007-8-1");
DateTime DT2 = Convert.datetime ("2007-8-15");
TimeSpan span = dt2. Subtract (DT1);
int Daydiff = span. Days + 1;
Calculate the number of days of the month in a year
-----------------------------------------------
int days = Datetime.daysinmonth (2007, 8);
days = 31;
Add one day to date, one day less
-----------------------------------------------
DateTime DT =datetime.now;
Dt. AddDays (1); Add one day
Dt. AddDays (-1);//Decrease One day
Other years method similar ...
Convert Date function in Oracle sql
-----------------------------------------------
To_date ("2007-6-6", "yyyy-mm-dd");
To_date ("2007/6/6", "yyyy/mm/dd");
For the next set of data, how to find a table that contains September records:
Cggc_stratdate cggc_enddate
=========================================
2007-8-4 2007-9-5
2007-9-5 2007-9-20
2007-9-22 2007-10-5
SELECT * from TABLE
(To_date (' 2007/9/1 ', ' yyyy/mm/dd ') between cggc_stratdate
and Cggc_enddate OR cggc_stratdate >=to_date (' 2007/9/1 ', ' yyyy/mm/dd ')
and Cggc_enddate<=to_date (' 2007/9/30 ', ' yyyy/mm/dd ') "
OR to_date (' 2007/9/30 ', ' yyyy/mm/dd ') between cggc_stratdate
and Cggc_enddate) ORDER by Cggc_stratdate ASC

//This year, formatted with ToString characters we also easily calculate the first and last day of the year
DateTime.Parse (DateTime.Now.ToString ("yyyy-01-01")). ToShortDateString ();
DateTime.Parse (DateTime.Now.ToString ("yyyy-01-01")). AddYears (1). AddDays (-1). ToShortDateString ();
//Last year, no more explaining
DateTime.Parse (DateTime.Now.ToString ("yyyy-01-01")). AddYears (-1). ToShortDateString ();
DateTime.Parse (DateTime.Now.ToString ("yyyy-01-01")). AddDays (-1). ToShortDateString ();
//Next year
DateTime.Parse (DateTime.Now.ToString ("yyyy-01-01")). AddYears (1). ToShortDateString ();
DateTime.Parse (DateTime.Now.ToString ("yyyy-01-01")). AddYears (2). AddDays (-1). ToShortDateString ();

This quarter, many people will feel the difficulty here, need to write a long process to judge. In fact, we all know that four quarters a year, three months a quarter
First we push the date to the first month of the quarter, and then the first day of the month is the first day of the quarter.
DateTime.Now.AddMonths (0-((datetime.now.month-1)% 3)). ToString ("yyyy-mm-01");
Similarly, the last day of the quarter is the first day of the next quarter minus one
DateTime.Parse (DateTime.Now.AddMonths (3-((datetime.now.month-1)% 3)). ToString ("yyyy-mm-01")). AddDays (-1). ToShortDateString ();
Next quarter
DateTime.Now.AddMonths (3-((datetime.now.month-1)% 3)). ToString ("yyyy-mm-01");
DateTime.Parse (DateTime.Now.AddMonths (6-((datetime.now.month-1)% 3)). ToString ("yyyy-mm-01")). AddDays (-1). ToShortDateString ();
Last quarter
DateTime.Now.AddMonths ( -3-((datetime.now.month-1)% 3)). ToString ("yyyy-mm-01");
DateTime.Parse (DateTime.Now.AddMonths (0-((datetime.now.month-1)% 3)). ToString ("yyyy-mm-01")). AddDays (-1). ToShortDateString ();

How to get how many days a month

int M=system.datetime.daysinmonth (system.datetime.now.year,system.datetime.now.month);

Get the actual working day of a month (that is, excluding week 6th)

Call
int days =getdays (System.DateTime.Now));
private int getDays (System.DateTime date1)
{
int M=system.datetime.daysinmonth (date1. Year,date1. Month);
int mm=0;
for (int i=1;i<=m;i++)
{
System.DateTime Date=convert.todatetime (date1. year+ "-" +date1. month+ "-" +i);
Switch (date. DayOfWeek)
{
Case System.DayOfWeek.Monday:
Case System.DayOfWeek.Thursday:
Case System.DayOfWeek.Tuesday:
Case System.DayOfWeek.Wednesday:
Case System.DayOfWeek.Friday:
mm=mm+1;
Break

}
}
return mm;
}

Obtain a valid working day between any two dates (excluding week 6th) to obtain a valid working day between any two dates (excluding week 6th) #region Get a valid working day between any two dates (excluding weeks 6th)

Call
DateTime date1=convert.todatetime ("2005-10-20");
DateTime date2=convert.todatetime ("2005-11-01");
int days =getdays (DATE1,DATE2);
private int getDays (System.DateTime date1,system.datetime date2)
{
String M=datediff (Enumdatecompare.day,date1,date2). ToString ("F0");

int mm=0;
for (int i=0;i<=convert.toint32 (m); i++)
{
System.DateTime Date=convert.todatetime (date1. AddDays (i));
Switch (date. DayOfWeek)
{
Case System.DayOfWeek.Monday:
Case System.DayOfWeek.Thursday:
Case System.DayOfWeek.Tuesday:
Case System.DayOfWeek.Wednesday:
Case System.DayOfWeek.Friday:
mm=mm+1;
Break
}
}
return mm;
}
#endregion
Format output

Format Output #region format output
private void Page_Load (object sender, System.EventArgs e)
{
System.Globalization.DateTimeFormatInfo Mydtfi = new System.Globalization.CultureInfo ("en-us", false). DateTimeFormat;
China with ZH-CN
DateTime myDT =system.datetime.now;
Response.Write (Mydt.tostring ("F", Mydtfi));
/**//**//**//*
This code produces the following output.
FORMAT en-US EXAMPLE
CHAR VALUE of associated property, IF any
D 1/3/2002 m/d/yyyy (ShortDatePattern)
D Thursday, January, 2002 dddd, MMMM DD, yyyy (LONGDATEPATTERN)
F Thursday, January, 2002
F Thursday, January, 2002 12:00:00 AM dddd, MMMM dd, yyyy h:mm:ss TT (Fulldatetimepattern)
G 1/3/2002 AM
G 1/3/2002 12:00:00 AM
M January MMMM DD (Monthdaypattern)
M January MMMM DD (Monthdaypattern)
R Thu, Jan 2002 00:00:00 GMT ddd, dd MMM yyyy HH ': ' mm ': ' SS ' GMT ' (Rfc1123pattern)
R Thu, Jan 2002 00:00:00 GMT ddd, dd MMM yyyy HH ': ' mm ': ' SS ' GMT ' (Rfc1123pattern)
s 2002-01-03t00:00:00 yyyy '-' mm '-' dd ' T ' HH ': ' mm ': ' SS (Sortabledatetimepattern)
T-h:mm TT (Shorttimepattern)
T 12:00:00 AM h:mm:ss tt (Longtimepattern)
U 2002-01-03 00:00:00z yyyy '-' mm '-' dd HH ': ' mm ': ' SS ' Z ' (Universalsortabledatetimepattern)
U Thursday, January, 2002 8:00:00 AM
Y January, 2002 MMMM, YYYY (Yearmonthpattern)
Y January, 2002 MMMM, YYYY (Yearmonthpattern)
*/
}
#endregion

Get this week's Saturday and Sunday

Convertdatetoweek#region Convertdatetoweek
public static void Convertdatetoweek (DateTime date,out datetime firstdate,out datetime lastdate)
{
DateTime First=system.datetime.now;
DateTime Last=system.datetime.now;
Switch (date. DayOfWeek)
{Case System.DayOfWeek.Monday:
First=date. AddDays (-1);
Last=date. AddDays (5);
Break
Case System.DayOfWeek.Tuesday:
First=date. AddDays (-2);
Last=date. AddDays (4);
Break
Case System.DayOfWeek.Wednesday:
First=date. AddDays (-3);
Last=date. AddDays (3);
Break
Case System.DayOfWeek.Thursday:
First=date. AddDays (-4);
Last=date. AddDays (2);
Break
Case System.DayOfWeek.Friday:
First=date. AddDays (-5);
Last=date. AddDays (1);
Break
Case System.DayOfWeek.Saturday:
First=date. AddDays (-6);
Last=date;
Break
Case System.DayOfWeek.Sunday:
First=date;
Last=date. AddDays (6);
Break
}
Firstdate=first;
Lastdate=last;
}
#endregion
Call
DateTime Firstdate=system.datetime.now;
DateTime Lastdate=system.datetime.now;
Convertdatetoweek (date,out firstdate,out lastdate);
Get the current date is the week of the year
DateTime dt = Convert.todatetime ("2006-05-01");
int weeks = dt. DAYOFYEAR/7 + 1;

C # Format and usage of the current time given by datetime