Q:

Copying / Tarring Files that have been modified in the last 14 days

I have a server whose files are modified every so now and again.
We want to have a script or cron job that runs every 7 days and finds any php files that have been modified or created in the last 14 days and puts them in a tar or a zip file on the server so it can be downloaded.
This command finds the right files:
find . -name "*.php" -mtime -14 -print

What else do I need to do?

A:

if your list of files from find output is correct just pipe it to tar:
find . -name "*.php" -mtime -14 -print | xargs tar cvf backup.tar

You should check tar options in man. You might want use for example -p (preserve permissions), just look for useful options in man and use whatever you need.
and to add it to cron, the simplest way if your distro supports it, is to put your script in:
/etc/cron.weekly

otherwise you have to modfiy crontab:
crontab -e

and put there a line like:
0 3 * * 6 <user> <your script>

it runs a script at 3am every saturday, the last script is day of the week, 0 or 7 is sunday.
man 5 crontab:
 field          allowed values
          -----          --------------
          minute         0-59
          hour           0-23
          day of month   1-31
          month          1-12 (or names, see below)
          day of week    0-7 (0 or 7  is  Sun,  or  use
          names)

A:

cron's good.
You may want GNU tar's --files-from; xargs is dangerous here.  xargs is fine if the number of files is known to always be small, but if the list of files gets big, xargs restarting tar will toast all but the last n files.

