Yes, I was under the impression that IntervalMatch() includes both start and end values as well... So - with you - I am wondering why the reference date is greyed out.. Is it because start end end values are identical?!?
Thanks for your reply! date() is specified in my load script as having the standard format DD-MM-YYYY, so it should be OK. That date is BTW created to get a possibility to aggregate all created [Res. aanmaakdatum] (resolution up to 1/10000 second) to one single day per claim.