Welcome back from a 3 day holiday weekend. When I was younger my sleep habits were different on different days of the week.
Staying up late on the weekends to hang out with friends is typical when you are young.
Some folks continue to do this all of their lives, and they are probably less productive than they would be if they were in sync with their body clocks.
I found this article from RAB.com that can apply to all of us:
When You’re At Your Best
Schedule your most vital activities when you are at your physical and mental peak. You have a two to four-hour block of time during the day when you operate at peak efficiency.
Your concentration is keen, your creative powers are more acute, and your ability to do more than one thing at a time is sharper. Pinpoint this time and schedule your most important activities within this block of time.
Source: Adapted from You’re Working Too Hard to Make the Sale, by William T. Brooks, founder and CEO of The Brooks Group