Today would be a better day then on Tuesday to hive your bees. Although either day would be doable if you would like to wait until Wednesday to hive your packages you could do so. You will need to store the package bees between 50° and 60°. You will also have to check the feeder cans to ensure they have food. To do this you take the package and slowly rock it back-and-forth and listen for the sloshing of fluid in the feeder can. If you do not hear any sloshing it would be a good idea to spray the outside of the cage on all four sides and the top with sugar water. Twice a day once in the morning and once in the evening.
If you are scheduled for pick up tomorrow and can make it for pick up today, today is better than tomorrow. Come by 7pm anytime.