Torben,
that would be a solution. Another maybe less involved is to apply the following (untested) patch:
Index: ecommerce-utilities-procs.tcl
===================================================================
RCS file: /cvsroot/openacs-4/packages/ecommerce/tcl/ecommerce-utilities-procs.tcl,v
retrieving revision 1.12
diff -r1.12 ecommerce-utilities-procs.tcl
568a569
<blockquote> regsub -- {\.[0-9]+$} $ugly_date "" ugly_date
</blockquote>
590a592
<blockquote> regsub -- {\.[0-9]+$} $ugly_date "" ugly_date
</blockquote>
This will strip the sub-second portion from the timestamp.
/Bart