This is puzzling. Can you make me a 'developer' on test-ehr, and add this to the log4j.xml

    <logger name="org.labkey.api.data">
         <level value="debug"/>
        <appender-ref ref="SESSION"/>
    </logger>

This will make it possible for me to see the postgres SQL being generated.

I'm not sure how the date strings are being converted. I would use an explicit CAST('2011-03-01' AS TIMESTAMP), however, I don't think that explains what's going on.