Chronobiology gives answers to different questions in connection to a day-night rhythm. One of the questions is how the time frame within a day affects the success of students. The present research investigates a connection between knowledge and chronotype according to the time of the examination. The research is based on the MESSi questionnaire and carefully chosen selection tasks of the Matura examination of biology. We used the Matura exam tasks because it is a standardized test of knowledge examination with a determined time of execution. In this study, 309 students of the third and the fourth grades participated from four different general high schools in Slovenia. The data was collected via an online survey. We confirmed that MESSi was adequate for the Slovene population of students between 16 and 20 years old. The participants solved less than 50 % of the Matura exam correctly. Statistically, the grade did not affect the regularity of the answers to specific questions, and neither did time, when the tests were written. There was no connection found between the individual's chronotype and knowledge in any time frame. Meaning, the morning type of students did not have an advantage in solving the Matura tasks in comparison to the evening type. Students of both chronotypes solved the tasks equally successful. This kind of research was the first one conducted in this manner in our area.