What are the effects of sleeping late and waking up late?

Sleep cycle change: If you get in the habit oh a particular time cycle of going to bed and getting up it will probably become established and difficult to change. It can be changed though like in people who change work shifts.

Circadian rhythm: You may be a "night owl" type, who does better into the evening/night--as opposed to a "morning person" (who obviously would be at their best in the am). Fighting your predetermined preferences can cause some stress physiologically, but following it is ok...Unless you are late for work/school/etc.