Calculating weeks/days old if child is less than 1 month or 1 week old.

I am currently using =IF(DATE(YEAR(I3)+2,MONTH(I3),DAY(I3))-Q3>0,DATEDIF(I3,Q3,"m") & " m ",DATEDIF(I3,Q3,"y") & " y ")
I need to calculate weeks old if less than a month and days old if less than a week.

See my old thread:
http://www.excelforum.com/excel-form...=1#post3033638