3 Answer was missing the switch for the timestamp option, rendering the command useless to the purpose. Please delete the last line of the edit, it was required only because edits must be 6+ chars.
source | link

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

*edited to fix missing "-" for timestamp option

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

*edited to fix missing "-" for timestamp option

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

2 Answer was missing the switch for the timestamp option, rendering the command useless to the purpose. Please delete the last line of the edit, it was required only because edits must be 6+ chars.
source | link

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

*edited to fix missing "-" for timestamp option

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

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

*edited to fix missing "-" for timestamp option

1
source | link

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