Email date parser when right click on browser
<p>[EDIT] I rewrote the question to mention specifically the context menu. Thanks for the remark.</p>

<p>I'm looking to create a date parser for email, so that in case of text selection and right click, there will be an option in the context menu to identify the selected text (say <code>7/6/2011 10:30 meeting with John</code>) and add to my calendar (I'm using Google's calendar).</p>

<p>I was thinking of developing such a thing in Javascript, is there a way to hook up to the right-click context menu of the browser without the use of extensions? 
Or it's better to create desktop application that hooks up to the "copy" event?
Is there a library for date parsing on Javascript or others?</p>

<p>Thanks in advance.</p>
