Find regular expression for my twitter time stamp (PHP)

Find regular expression for my twitter time stamp (PHP)

I am trying to fix my twitter feed and I wanted to link my tweet's time
stamp to each individual tweet's page.
I created my function using a regular expression for my tweet's time stamp
but it just doesn't seem to work.
The format of the time stamp is about xx minute(s)/hour(s)/day(s) ago and
I used the bellow regular expression to describe it.
$tweet="/about + /[0-9] + / minute[s]|day[s] ago/";
It might be completely wrong, but I'm new in this, and I'd appreciate any
help.
Many thanks in advance!