NSDateFormatter的格式字符串

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateStyle:NSDateFormatterMediumStyle];

[dateFormatter setTimeStyle:NSDateFormatterShortStyle];

//[dateFormatter setDateFormat:@"hh:mm:ss"]

[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss.SSS"
];
//毫秒

NSLog(@"Date%@"
, [dateFormatter stringFromDate:[NSDate date]]);

[dateFormatter release];

Specifier	Description
%%	A '%' character
%a	Abbreviated weekday name
%A	Full weekday name
%b	Abbreviated month name
%B	Full month name
%c	Shorthand for “ %X %x ", the locale format for date and time
%d	Day of the month as a decimal number (01-31)
%e	Same as %d but does not print the leading 0 for days 1 through 9 (unlike strftime() , does not print a leading space)
%F	Milliseconds as a decimal number (000-999)
%H	Hour based on a 24-hour clock as a decimal number (00-23)
%I	Hour based on a 12-hour clock as a decimal number (01-12)
%j	Day of the year as a decimal number (001-366)
%m	Month as a decimal number (01-12)
%M	Minute as a decimal number (00-59)
%p	AM/PM designation for the locale
%S	Second as a decimal number (00-59)
%w	Weekday as a decimal number (0-6), where Sunday is 0
%x	Date using the date representation for the locale, including the time zone (produces different results from strftime() )
%X	Time using the time representation for the locale (produces different results from strftime() )
%y	Year without century (00-99)
%Y	Year with century (such as 1990)
%Z	Time zone name (such as Pacific Daylight Time; produces different results from strftime() )
%z	Time zone offset in hours and minutes from GMT (HHMM)