Coalesce nullif date datetime HSQL

Sorry to bother you guys with this general question, but I’m sure somebody knows the solution:

I’m trying to get the maximum date or some “early” date, if there is no matching date:
This is my datasource query definition:

select e from basicdemo$Transaction e
where = :ds$articleDs
and e.recordedTime >= (select coalesce(max(f.recordedTime), ‘2000-01-01’)
from basicdemo$Transaction f
where f.type = ‘absolute’)

The part of interest which doesn’t work is: coalesce(max(f.recordedTime), ‘2000-01-01’)
It throws: HsqlException: data exception: invalid datetime format

If I use: coalesce(max(f.recordedTime), date ‘2000-01-01’) it produces an “Internal Error”

It should be easy but I don’t get it.