FileMaker is quite forgiving about input data and will let you put non-properly formatting data in a date field unless you define it to strictly be a date (same thing happens with number fields). What happens is someone is putting in information that has a character or space or something that makes it an invalid date and it sorts all the dates first and most recent record is usually the date that is not properly formatted. I always define my dates strictly date formats to avoid such issues. By the way, 8 isn't supported anymore and I think your ability to upgrade from it ends this Fall, so you might consider upgrading soon.