What is my real biological clock? (About MCTQ)
A scientific method to find your body's true schedule, not a generic questionnaire.
How is it different from general questionnaires?
Most common sleep tests ask subjective questions like "Do you prefer waking up in the morning or evening?"
However, the MCTQ (Munich ChronoType Questionnaire), designed by Prof. Till Roenneberg and his team at Ludwig Maximilian University of Munich (LMU), is based on actual sleep timing data. It records precisely when you prepare for sleep, fall asleep, and wake up on work days and free days.
By correcting for the sleep debt accumulated during weekdays and adjusting weekend sleeping habits, it reverse-calculates your true corrected mid-sleep time ($MSF_{sc}$).
Weekday vs Weekend Misalignment: Social Jetlag (SJL)
Social Jetlag refers to the difference between your mid-sleep point on work days and free days.
For example, if you sleep at 11:30 PM and wake at 6:30 AM on weekdays (mid-sleep 3:00 AM), but sleep at 1:30 AM and wake at 9:30 AM on weekends (mid-sleep 5:30 AM), your Social Jetlag is 2.5 hours. This means you experience physiological stress (circadian misalignment) equivalent to flying to a country with a 2.5-hour time difference (like Vietnam or Thailand) every weekend and returning on Monday.