Another way that you could look at it is if you lose some income on the farm by having a full time job. If you can take time off and get your crop planted and harvested on time then you are not losing any farm income from the job. We have had springs where there have only been about 4 or 5 days fit so you could drive in the fields to plant corn. If your happened to be working a couple of those days and didn't get your crop planted on time it could cost more then a years income from the off farm job to make up for the farm lose.