How much calories are too much to consume at once?

How much calories are to much to consume at once? Would eating 1000 cal for breakfast be to much, as i will be starting a summer job soon and the time from breakfast to lunch will be about 5 hours, im used to eating every 2-3 hours. (i eat about 4000 cal a day)

I suppose it depends on what you want, i for example am trying to put on some serious muscle mass at the moment and sometimes consume over 1000 calories just for breakfast (some days i just cant help it). But i am confident that when i want to get shredded in 2-3 months time, i will accomplish that.