It's sad that different chronotypes aren't taken into account for work schedules. There are many an individual contributor, and manager, who naturally outperform outside of the usual 9-5 framework. Formally it's called Delayed Sleep Phase Syndrome (DSPS). Practically these are the people whose ancestors were guarding the tribe keeping it safe at night.
Those who like to start their day mid morning and those who like to start their day early morning. To accommodate everyone a lot of companies use a standard "core time" of 10-2 where everyone needs to be in the office.