How can I change the date modified/created of a file?

Question

Is there a way to change the date when a file was modified/created (which is shown in Nautilus or with the ls -l command)? Ideally I am looking for a command which can change the date/time stamps of a whole bunch of files to a certain amount of time earlier or later (e.g. +8 hours or -4 days etc.).

Answer 1

You can change the modification time of a file using the touch command:

touch filename

By default this will set the file's modification time to the current time, but there are a number of flags, such as the -d flag to pick a particular date. So for example, to set a file as being modified two hours before the present, you could use the following:

touch -d "2 hours ago" filename

If you want to modify the file relative to its existing modification time instead, the following should do the trick:

touch -d "$(date -r filename) - 2 hours" filename

If you want to modify a large number of files, you could use the following:

find DIRECTORY -print | while read filename; do
    # do whatever you want with the file
    touch -d "$(date -r "$filename") - 2 hours" "$filename"
done

You can change the arguments to find to select only the files you are interested in. If you only want to update the file modification times relative to the present time, you can simplify this to:

find DIRECTORY -exec touch -d "2 hours ago" {} +

This form isn't possible with the file time relative version because it uses the shell to form the arguments to touch.

As far as the creation time goes, most Linux file systems do not keep track of this value. There is a ctime associated with files, but it tracks when the file metadata was last changed. If the file never has its permissions changed, it might happen to hold the creation time, but this is a coincidence. Explicitly changing the file modification time counts as a metadata change, so will also have the side effect of updating the ctime.

Answer 2

Thanks for the help. This worked for me:

In the terminal go to the directory for date-edit. Then type:

find -print | while read filename; do
    # do whatever you want with the file
    touch -t 201203101513 "$filename"
done

You wil see a ">" after you hit enter, exept for the last time -> "done".

Note: You may want to change "201203101513"

"201203101513" = is the date you want for all the files in this directory.

See my webpage

Answer 3

This little script at least works for me

#!/bin/bash

# find specific files
files=$(find . -type f -name '*.JPG')

# use newline as file separator (handle spaces in filenames)
IFS=$'\n'

for f in ${files}
do
 # read file modification date using stat as seconds
 # adjust date backwards (1 month) using date and print in correct format 
 # change file time using touch
 touch -t $(date -v -1m -r $(stat -f %m  "${f}") +%Y%m%d%H%M.%S) "${f}"
done

Answer 4

It's been a long time since I wrote any kind of Unix program, but I accidentally set the year incorrectly on a bunch of Christmas photos, and I knew if I didn't change the date from 2015 to 2014 it would be a problem later on.

Maybe, this is an easy task, but I didn't find any simple way to do it.

I modified a script I found here, which originally was used to modify the date by minus one month.

Here's the original script:

#!/bin/bash

# find specific files
files=$(find . -type f -name '*.JPG')

# use newline as file separator (handle spaces in filenames)
IFS=$'\n'

for f in ${files}
do
 # read file modification date using stat as seconds
 # adjust date backwards (1 month) using date and print in correct format 
 # change file time using touch
 touch -t $(date -v -1m -r $(stat -f %m  "${f}") +%Y%m%d%H%M.%S) "${f}"
done

Here's my modified script that forced the date to the year "2014":

#!/bin/bash 

# find specific files
#files=$(find . -type f -name '*.JPG')

# use newline as file separator (handle spaces in filenames)
IFS=$'\n'

for f in $*
do
 # read file modification date using stat as seconds
 # adjust date backwards (1 month) using date and print in correct format 
 # change file time using touch
 touch -t $(date -v +1y -r $(stat -f %m  "${f}") +2014%m%d%H%M.%S) "${f}"
done

I now realize I could have done a more generic version:

#!/bin/bash 

# find specific files
#files=$(find . -type f -name '*.JPG')

# use newline as file separator (handle spaces in filenames)
IFS=$'\n'

for f in $*
do
 # read file modification date using stat as seconds
 # adjust date backwards (1 month) using date and print in correct format 
 # change file time using touch (+1y adds a year "-1y" subtracts a year)
 # Below line subtracts a year
 touch -t $(date -v -1y -r $(stat -f %m  "${f}") +%Y%m%d%H%M.%S) "${f}"
 # Below line adds a year
 # touch -t $(date -v +1y -r $(stat -f %m  "${f}") +%Y%m%d%H%M.%S) "${f}"
done

To use this file you would need to write it and

chmod +x fn

to execute:

./fn files-to-change

fn=your-file-name-that-is-your-command

Example

./fn *.JPG

will change the date by minus one year in the directory where you are.

Answer 5

Easiest way - accessed modified will be the same:

touch -a -m t 201512180130.09 fileName.ext

Where:

-a = accessed
-m = modified
t  = timestamp - use [[CC]YY]MMDDhhmm[.ss] time format

If you wish to use NOW just drop the t and the timestamp

To verify they are all the same: stat fileName.ext

See: touch man

Answer 6

just change date and time in settings. then save your file, it automatically changes