A full backup has not been taken for database

Can the  alarm  "A full backup has not been taken for database" handle a threshold of 1.05 instead of whole numbers 1, 2, 3. All my databases get backed up at the same time and sometime a few databases may take a little longer then the 24 hours defined. I was wondering if I change the threshold to 1.05  then it would not fire the alarm until 25.2 hours. I am going to test it tonight but thought I would ask incase I can get an answer earlier. 

Thanks