st: Calculating date giving syntax error

["Ziad El-Khatib" <Ziad.El-Khatib@ki.se>]

Hi,
I am trying to calculate age of patients it gives 'type mismatch
error' (r(109)) for both of the following commands:

gen momage=scrndte-dobmom

and

gen momage=(scrndte-dobmom)/365.25



Any tips how to deal with it?


Thank you and best regards
ziad
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/