I agree with Brapple. Especially a big company like target, they dont want to be second to anyone else. If you dont show or call off the shifts you cant work, i'm sure you would be fired at either job. in that case you'd have to weigh consequences and decide which job to stick with. or try reasoning with one or the other, some managers are reasonable, so find one of your managers that will understand.
Its stupid the fact that these large companies do realize that their employees have needs. Don't want to dive into Marx, but they kind of exploit their labor force for their own gain. If it were possible to outsource retail/cashier/stock boy/truck diver jobs they would....