Linux Date 指令運用

利用date 指令來取得,格式如下 
date "+%Y %m %d %H:%M:%S"

Display the current time in the given FORMAT, or set the system date.

-d, --date=STRING

              display time described by STRING, not `now'

FORMAT controls the output:
%Y     year (1970...)
%m     month (01..12)
%d     day of month (01..31)
%H     hour (00..23)
%M     minute (00..59)
%S     second (00..60); the 60 is necessary to accommodate a leap  second 

當天

date +%Y%m%d

前一天
# date --date='1 days ago' +%Y%m%d
# date -d '1 days ago' +%Y%m%d
# date -d yesterday +%Y%m%d
明天
# date --date='1 days' +%Y%m%d
# date -d '1 days' +%Y%m%d
# date -d tomorrow +%Y%m%d