title: difference between mtime +0 and mtime 0
body: <p>I an using mtime with find . I am duing it for first time .
  I see a script which moves file from one location to other.</p>
  
  <pre><code> `find . \ -mtime +0 -exec mv {} target \ ;`
  </code></pre>
  
  <p>I want to understand does +0 means only for file created before 24 hrs?
     Now as these files are moved to target i also want to modify there permission to one appropiate for everyone to read. So i used the command </p>
  
  <pre><code> `find target -mtime 0 -exec chmod 644 {} \;`
  </code></pre>
  
  <p>I want to really get hole of difference between usage of +0 , 0 . Does 0 only signified between now and 24 hr while +0 is from 24 and more old ? My main purpose here is to modify the permission of all files in target dir where i have just moved them . As they can be many i jst want to run one command and do it all. </p>