NAME
touch - change file timestamps
SYNOPSIS
touch [OPTION]... FILE...
DESCRIPTION
Update the access and modification times of each FILE to the current time.

Mandatory arguments to long options are mandatory for short options too.

-a
change only the access time
-c, --no-create
do not create any files
-d, --date=STRING
parse STRING and use it instead of current time
-f
(ignored)
-m
change only the modification time
-r, --reference=FILE
use this file's times instead of current time
-t STAMP
use [[CC]YY]MMDDhhmm[.ss] instead of current time
--time=WORD
set time given by WORD: access atime use (same as -a) modify mtime (same as -m)
--help
display this help and exit
--version
output version information and exit
Note that the -d and -t options accept different time-date formats.