DateTime Format

显示时间的格式很多，现总结如下:

Format	Description	Example
d	Short date	4/11/2008
D	Long date	Friday, April 11, 2008
t	Short time	4:46 PM
T	Long time	4:48:27 PM
f	Long date & short time	Friday, April 11, 2008 4:48 PM
F	Long date & long time	Friday, April 11, 2008 4:50:02 PM
g	Short date & short time	4/11/2008 4:53 PM
G	Short date & long time	4/11/2008 4:53:49 PM
M	Month	April 11
R	RFC1123	Fri, 11 Apr 2008 16:55:07 GMT
s	Sortable	2008-04-11T16:56:28
u	Universal sortable(invariant)	2008-04-11 16:57:03Z
U	Universal sortable	Friday, April 11, 2008 8:58:28 AM
Y	year	April, 2008
o	Round trip(local)	2008-04-11T17:00:47.5986364+08:00
dd	day in month	14(the full date:2008-4-14)
ddd	day in week, display in three characters	Mon(the full date:2008-4-14)
dddd	day in week, display in full name.	Monday(the full date:2008-4-14)
hh	hour, 0~12	06
HH	hour, 0~23	18
d MMMM yyyy		16 April 2008

convert to GMT Time

string date = "2009-02-25 16:13:00Z"; // Coordinated Universal Time string from DateTime.Now.ToUniversalTime().ToString("u");

DateTime localDateTime = DateTime.Parse(date); // Local .NET timeZone.

DateTime utcDateTime = localDateTime.ToUniversalTime();



// ID from "HKEY_LOCAL_MACHINE"Software"Microsoft"Windows NT"CurrentVersion"Time Zone"

// See http://msdn.microsoft.com/en-us/library/system.timezoneinfo.id.aspx

string nzTimeZoneKey = "New Zealand Standard Time";

TimeZoneInfo nzTimeZone = TimeZoneInfo.FindSystemTimeZoneById(nzTimeZoneKey);

DateTime nzDateTime = TimeZoneInfo.ConvertTimeFromUtc(utcDateTime, nzTimeZone);

2> DateTime 方法：

     判断一个月有几天： DateTime.DayInMonth(int iyear, int imonth)

3>sqlserver date 处理

select CONVERT(varchar, getdate(), 120 )
2004-09-12 11:06:08

select replace(replace(replace(CONVERT(varchar, getdate(), 120 ),"'-"',"'"'),"' "',"'"'),"':"',"'"')
20040912110608

select CONVERT(varchar(12) , getdate(), 111 )
2004/09/12

select CONVERT(varchar(12) , getdate(), 112 )
20040912

select CONVERT(varchar(12) , getdate(), 102 )
2004.09.12

select CONVERT(varchar(12) , getdate(), 101 )
09/12/2004

select CONVERT(varchar(12) , getdate(), 103 )
12/09/2004

select CONVERT(varchar(12) , getdate(), 104 )
12.09.2004

select CONVERT(varchar(12) , getdate(), 105 )
12-09-2004

select CONVERT(varchar(12) , getdate(), 106 )
12 09 2004

select CONVERT(varchar(12) , getdate(), 107 )
09 12, 2004

select CONVERT(varchar(12) , getdate(), 108 )
11:06:08

select CONVERT(varchar(12) , getdate(), 109 )
09 12 2004 1

select CONVERT(varchar(12) , getdate(), 110 )
09-12-2004

select CONVERT(varchar(12) , getdate(), 113 )
12 09 2004 1

select CONVERT(varchar(12) , getdate(), 114 )
11:06:08.177