The new date format is implemented already. It will be deployed along with other changes (mainly RPSL) in the next few months. Pete Ashdown on Fri, 19 Dec 1997 13:50:03 -0700 (MST) said:

I tried this today whilst updating my AS:

changed: pashdown@xmission.com 19971218

*ERROR*: date part of "changed"not in YYMMDD format

I know it isn't going to break any critical transactions, but I'd suggest moving to YYYYMMDD.