The article is very interesting and relevant. This paper reports on the importance of sleep for better well-being. I have some minor changes that the authors should revise. There are also some parts/procedures in the text that need clarification. Please see below all the points and attached the authors may find the pdf with the comments if find it more useful.

1. A reference is missing (line 39 after "... calendar age")
2. Section Procedures (line 75) is missing when was the study performed. Please provide the month and year of data collection. This applies also to study 2.
3. In the statistical procedures sections, the level of significance used in the tests is not provided.
4. Please clarify. Which experimental sessions? What was the experiment? (line 119 is not clear)
5. Here should also be clarified.
   Participants were assigned for morning or afternoon sessions according to reported chronotype? (line 124-125)
6. From lines 128-130 no need to mention the procedure for blood sample collection since these samples are not going to be presented in this report
7. In all your graphs where is related to calendar age. The authors have an error "calender age" Please correct this error in all graphs