Please see ftp://ftp.openldap.org/incoming/pierangelo-masarati-2009-08-13-now2.1.c for a minimal implementation that instantiates a specific syntax (that only allows the empty string) and works for generalizedTime as well as CSN syntaxes. Valid filters are

(createTimestamp:nowOrEarlier:=)

(entryCSN:nowOrLater:=)

Please check the code, and see if you agree in the attributions (significantly, in releasing the copyright to the OpenLDAP foundation). Also, note that an OID from OpenLDAP's devel arc has been used, but not yet allocated. I plan to do it shortly.

p.