Query range function: Less than date and not date null

There is a lessThanDate query function in AX, but it also selects blank dates.

Here is a suggestion for a similar function, that does not include the blank dates:

public static str lessThanDateAndNotNull(int relativeDays = 0)
{     
    utcdatetime  currentDateTime;      

    currentDateTime = DateTimeUtil::applyTimeZoneOffset(DateTimeUtil::getSystemDateTime(), 
DateTimeUtil::getUserPreferredTimeZone());      

    return SysQuery::value(dateNull() + 1) + ' .. ' +            
           SysQuery::value(DateTimeUtil::date(DateTimeUtil::addDays(currentDateTime, relativeDays - 1)));  
}