The following is not parsed:
lastEarthQuake DURING OR AFTER 2006-11-30T01:30:00Z
The filter is parsed just fine using just "AFTER", but it seems the parser cannot handle "DURING OR AFTER" even if the CQL spec considers it valid. The ECQL parser suffers from the same problem.
Haven't tried, but have the sneaking suspect that BEFORE OR DURING is not handled either