几种Unix程序的日期格式表达方法

H hour (00..23)
I hour (01..12)
k hour ( 0..23)
l hour ( 1..12)
M minute (00..59)
p locale's AM or PM
r time， 12-hour (hh:mm:ss [AP]M)
S second (00..61)
T time， 24-hour (hh:mm:ss)
X locale's time representation (H:M:S)
Z time zone (e.g.， EDT)， or nothing if no time zone is determinable

a locale's abbreviated weekday name (Sun..Sat)
A locale's full weekday name， variable length (Sun-
day..Saturday)
b locale's abbreviated month name (Jan..Dec)
B locale's full month name， variable length (Jan-
uary..December)
c locale's date and time (Sat Nov 04 12:02:33 EST
1989)
d day of month (01..31)
D date (mm/dd/yy)
h same as b
j day of year (001..366)
m month (01..12)
U week number of year with Sunday as first day of
week (00..53)
w day of week (0..6)
W week number of year with Monday as first day of
week (00..53)
x locale's date representation (mm/dd/yy)
y last two digits of year (00..99)
Y year (1970...)

%a locale's abbreviated weekday name (Sun..Sat)
%A locale's full weekday name， variable length (Sunday..Saturday)
%b locale's abbreviated month name (Jan..Dec)
%B locale's full month name， variable length (January..December)
%c locale's date and time (Sat Nov 04 12:02:33 EST 1989)
%C century (year divided by 100 and truncated to an integer)
[00-99]
%d day of month (01..31)
%D date (mm/dd/yy)
%e day of month， blank padded ( 1..31)
%F same as %Y-%m-%d
%g the 2-digit year corresponding to the %V week number
%G the 4-digit year corresponding to the %V week number
%h same as %b
%H hour (00..23)
%I hour (01..12)
%j day of year (001..366)
%k hour ( 0..23)
%l hour ( 1..12)
%m month (01..12)
%M minute (00..59)
%n a newline
%N nanoseconds (000000000..999999999)
%p locale's upper case AM or PM indicator (blank in many locales)
%P locale's lower case am or pm indicator (blank in many locales)
%r time， 12-hour (hh:mm:ss [AP]M)
%R time， 24-hour (hh:mm)
%s seconds since '00:00:00 1970-01-01 UTC' (a GNU extension)
%S second (00..60); the 60 is necessary to accommodate a leap sec-
ond
%t a horizontal tab
%T time， 24-hour (hh:mm:ss)
%u day of week (1..7); 1 represents Monday
%U week number of year with Sunday as first day of week (00..53)
%V week number of year with Monday as first day of week (01..53)
%w day of week (0..6); 0 represents Sunday
%W week number of year with Monday as first day of week (00..53)
%x locale's date representation (mm/dd/yy)
%X locale's time representation (%H:%M:%S)
%y last two digits of year (00..99)
%Y year (1970...)
%z RFC-2822 style numeric timezone (-0500) (a nonstandard extension)
%Z time zone (e.g.， EDT)， or nothing if no time zone is determinable

a 小写的上午和下午值 am 或 pm
A 大写的上午和下午值 AM 或 PM
B Swatch Internet 标准时 000 到 999
d 月份中的第几天，有前导零的 2 位数字 01 到 31
D 星期中的第几天，文本表示，3 个字母 Mon 到 Sun
F 月份，完整的文本格式，例如 January 或者 March January 到 December
g 小时，12 小时格式，没有前导零 1 到 12
G 小时，24 小时格式，没有前导零 0 到 23
h 小时，12 小时格式，有前导零 01 到 12
H 小时，24 小时格式，有前导零 00 到 23
i 有前导零的分钟数 00 到 59
I 是否为夏令时 如果是夏令时为 1，否则为 0
j 月份中的第几天，没有前导零 1 到 31
l(“L”的小写字母) 星期几，完整的文本格式 Sunday 到 Saturday
L 是否为闰年 如果是闰年为 1，否则为 0
m 数字表示的月份，有前导零 01 到 12
M 三个字母缩写表示的月份 Jan 到 Dec
n 数字表示的月份，没有前导零 1 到 12
O 与格林威治时间相差的小时数 例如:+0200
r RFC 822 格式的日期 例如:Thu， 21 Dec 2000 16:01:07 +0200
s 秒数，有前导零 00 到 59>
S 每月天数后面的英文后缀，2 个字符 st，nd，rd 或者 th。可以和 j 一起用。
t 给定月份所应有的天数 28 到 31

find . -printf "%TY-%Tm-%Td %TH:%TM:%TS \n"
date +"%Y-%m-%d %H:%M:%S"
echo date ("Y-m-d H:i:s");
?>

2005-2-9 05:08:02
date +"%Y-%-m-%-d %-H:%-M:%-S"
2005-2-9 9:08:02
echo date ("Y-n-j G:i:s");
?>