Ldap timestamp search

Hi there!!!
I had to produce an incremental ldif file from an ldap server. This file had to have all ldap entries modified from a certain date (for example 1st of Febrary 2010). But the issue was not as easy as it sounds, mainly because i had to guess what was the search string that provided a valid filter in order to get the desired results.
The format is as follows:
YYYYMMDDhhmmssZ
4 digit Year
2 digits Month
2 digits Day
2 digits hour
2 digits minute
2 digits second
End with "Z" char
Example:

ldapsearch -x -H ldaps://A.B.C.D:636 -D "cn=admin,o=demo" -W -b "ou=users,o=kasa" "modifyTimestamp>=20100201000000Z" >tst.ldif

I hope that it will be usefull for you.