C # date format

# datetime Date Formatting

In C #, DateTime is a type that contains a date and time that can be converted to multiple string formats based on the arguments passed in to ToString () when this type is converted to a string by ToString ().

Directory

1. Classification

2. Format type

3. Custom Format types

1. Classification

DateTime calls to ToString () Pass in parameters that can be divided into standard and custom two types:

1) Format: The system comes with, into a specific single character can be converted to the system has been set.

2) Custom: Free combination of date codes (Y, M, D, H, M, S, f) to display rich date formats.

2. Format type

Note : Transferring to a specific single character can be converted to a format that is already set by the system.

2.1 Format Source

The date and time format can be set in the Regional and Language (location: Control Panel → regional and language) options in Windows systems.

The categories that can be set are: Short date, long date, short time, long time, etc.

When you call ToString () for conversion, many of the conversions are made by combining the 4 categories above.

2.2 Symbol Comparison 2.2.1 Environment

. NET version : 4.0

system version : Win7

format Information :

2.2.2 Table

Symbol	Grammar	Example (2016-05-09 13:09:55:2350)	Format description
Y	DateTime.Now.ToString ()	2016/5/9 13:09:55	Short Date long time
D	DateTime.Now.ToString ("D")	2016/5/9	Short Date
D	DateTime.Now.ToString ("D")	May 9, 2016	Long Date
F	DateTime.Now.ToString ("f")	May 9, 2016 13:09	Long Date short time
F	DateTime.Now.ToString ("F")	May 9, 2016 13:09:55	Long Date long time
G	DateTime.Now.ToString ("g")	2016/5/9 13:09	Short Date short time
G	DateTime.Now.ToString ("G")	2016/5/9 13:09:55	Short Date long time
T	DateTime.Now.ToString ("t")	13:09	Short time
T	DateTime.Now.ToString ("T")	13:09:55	Long time
U	DateTime.Now.ToString ("u")	2016-05-09 13:09:55z
U	DateTime.Now.ToString ("U")	May 9, 2016 5:09:55	Long date and long time of the Prime Meridian
M	DateTime.Now.ToString ("m")	May 9
M	DateTime.Now.ToString ("M")	May 9
R	DateTime.Now.ToString ("r")	Mon, 13:09:55 GMT
R	DateTime.Now.ToString ("R")	Mon, 13:09:55 GMT
Y	DateTime.Now.ToString ("y")	May 2016
Y	DateTime.Now.ToString ("Y")	May 2016
O	DateTime.Now.ToString ("o")	2016-05-09t13:09:55.2350000
O	DateTime.Now.ToString ("O")	2016-05-09t13:09:55.2350000
S	DateTime.Now.ToString ("s")	2016-05-09t13:09:55

2.3 Example Diagram

2.4 Win2003 Version

The '-' symbol replaces the '/' symbol in Win2003, D, G, and G in the default format (short date format: yyyy-m-d).

3. Custom Format types

Developers can freely combine date and time formats with English characters (Y, M, D, H, M, S, f), respectively (year, month, day, hour, minute, second, and millisecond).

3.1 Symbol Comparison Chart

. NET version : 4.0

system version : Win7

Symbol	Description	Grammar	Example (2016-05-09 13:09:55:2350)
Yy	Two digits after the year	DateTime.Now.ToString ("yy")	DateTime.Now.ToString ("yy"); = 16
yyyy	4-bit year	DateTime.Now.ToString ("yyyy")	DateTime.Now.ToString ("yyyy"); = 2016
Mm	two-digit month; 0 padding in front of singular month	DateTime.Now.ToString ("MM")	DateTime.Now.ToString ("MM"); = 05
Dd	Number of days	DateTime.Now.ToString ("dd")	DateTime.Now.ToString ("DD"); = 09
Ddd	Weeks	DateTime.Now.ToString ("ddd")	DateTime.Now.ToString ("ddd"); = Monday
dddd	Day of the Week	DateTime.Now.ToString ("dddd")	DateTime.Now.ToString ("dddd"); = Monday
hh	Number of hours in a 12-hour system	DateTime.Now.ToString ("hh")	DateTime.Now.ToString ("HH"); = 01
HH	Number of hours in a 24-hour system	DateTime.Now.ToString ("HH")	DateTime.Now.ToString ("HH"); = 13
Mm	Number of minutes	DateTime.Now.ToString ("mm")	DateTime.Now.ToString ("mm"); = 09
Ss	Number of seconds	DateTime.Now.ToString ("SS")	DateTime.Now.ToString ("SS"); = 55
Ff	Number of milliseconds first 2 bits	DateTime.Now.ToString ("ff")	DateTime.Now.ToString ("FF"); = 23
Fff	Number of milliseconds first 3 bits	DateTime.Now.ToString ("FFF")	DateTime.Now.ToString ("fff"); = 235
Ffff	Number of milliseconds first 4 bits	DateTime.Now.ToString ("ffff")	DateTime.Now.ToString ("FFFF"); = 2350
Separator	You can use separators to separate the days of the month and seconds. Contains values that are:-,/,: etc. non-key characters	DateTime.Now.ToString ("Yyyy-mm-dd HH:mm:ss:ffff"); = 2016-05-09 13:09:55:2350 DateTime.Now.ToString ("Yyyy/mm/dd HH:mm:ss:ffff"); = 2016/05/09 13:09:55:2350 DateTime.Now.ToString ("Yyyy/mm/dd HH:mm:ss:ffff dddd"); = 2016/05/09 13:09:55:2350 Monday

3.2 Example Diagram

Https://www.cnblogs.com/polk6/p/5465088.html

C # date format