touch [OPTION]... FILE...
Update the access and modification times of each FILE to the current
time.
A FILE argument that does not exist is created empty, unless -c or -h
is supplied.
A FILE argument string of - is handled specially and causes touch to
change the times of the file associated with standard output.
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)
-h, --no-dereference
affect each symbolic link instead of any referenced file (useful
only on systems that can change the timestamps of a symlink)
-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
change the specified time: WORD is access, atime, or use: equiv-
alent to -a WORD is modify or mtime: equivalent to -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.