sleeping in a bed with the phantoms

so I was testing phantoms. I had not set my spawn point. while it was night and the phantoms were there I clicked on and off the bed for less then 2 seconds. just to set my spawn location. I then had to wait another 4 days to see a phantom. I would think that "sleeping" would be sleeping a whole night untill morning not just a spawn set. but thats up to you devs to decide.