omg, dump all that replace stuff, the $duration2 works just like $duration, BUT it outputs its result just like how you wanted.

...Birthday:{ say 0,4 <Did you know?> 0,2 It is $duration2($calc($ctime(february 20 2006 12:00) - $ctime)) until my next birthday!! 0,3 <20th February>  }

PS: the SAY doesnt need the // you only need // or / when typing a command in on the text line.