date命令说明

基本使用格式：

date [-d "time-to-display"] +"format-to-display"

-d指定要显示的时间，如果不指定默认为当前时间；后边的+后的字符串为指定的输出格式，类式C的print的格式。常用示例如下：

date -d "1 day ago" +"%Y-%m-%d"
date -d "30 day ago" +"%Y-%m-%d"
date -d "+ 1 day" +"%Y-%m-%d"
date -d "- 1 month" +"%Y-%m-%d"
date -d "" +"%Y-%m-%d"
date -d "" +"输出为：%Y-%m-%d"

支持的输出项：

       %a     locale’s abbreviated weekday name (e.g., Sun)

       %A     locale’s full weekday name (e.g., Sunday)

       %b     locale’s abbreviated month name (e.g., Jan)

       %B     locale’s full month name (e.g., January)

       %c     locale’s date and time (e.g., Thu Mar   :: )

       %C     century; like %Y, except omit last two digits (e.g., )

       %d     day of month (e.g, )

       %D     date; same as %m/%d/%y

       %e     day of month, space padded; same as %_d

       %F     full date; same as %Y-%m-%d

       %g     last two digits of year of ISO week number (see %G)

       %G     year of ISO week number (see %V); normally useful only with %V

       %h     same as %b

       %H     hour (..)

       %I     hour (..)

       %j     day of year (..)

       %k     hour ( ..)
       %l     hour ( ..)

       %m     month (..)

       %M     minute (..)

       %n     a newline

       %N     nanoseconds (..)

       %p     locale’s equivalent of either AM or PM; blank if not known

       %P     like %p, but lower case

       %r     locale’s -hour clock time (e.g., :: PM)

       %R     -hour hour and minute; same as %H:%M

       %s     seconds since -- :: UTC

       %S     second (..)

       %t     a tab

       %T     time; same as %H:%M:%S

       %u     day of week (..);  is Monday

       %U     week number of year, with Sunday as first day of week (..)

       %V     ISO week number, with Monday as first day of week (..)

       %w     day of week (..);  is Sunday

       %W     week number of year, with Monday as first day of week (..)

       %x     locale’s date representation (e.g., //)

       %X     locale’s time representation (e.g., ::)

       %y     last two digits of year (..)

       %Y     year

       %z     +hhmm numeric timezone (e.g., -)

       %:z    +hh:mm numeric timezone (e.g., -:)

       %::z   +hh:mm:ss numeric time zone (e.g., -::)

       %:::z  numeric time zone with : to necessary precision (e.g., -, +:)

       %Z     alphabetic time zone abbreviation (e.g., EDT)