January exams...Do they really work?

Today, here I am, Christmas is about to start and I do not stop thinking about the great time I am going to spend with my family and friends here in my town and how much I have missed them. However, while I am excited to see my loved ones and stay again at home, suddenly, I have realized that maybe these Christmas holidays are not going to be as nice as they could be... Why do I think this? Because I know how much I must study for my university exams and the time this will require.
After wondering what the aim of doing exams in January could be, I still do not understand why universities all around Spain choose January as the month for official exams. It seems to me as unlogical that students have to get ready for such an important califications in their degree after the longest period of celebration we have in our country. Christmas is the time when all the people should enjoy with their family and their friends, the time to meet with those who are far away from us along the year, it is the only period to be carefree and just enjoy... But for everybody except university students.
Why? Why exams could not be later than January or even before Christmas? I think if the educational system chose other dates for exams, the results would be better because students would not study in a hurry all the subjects they are being passing over during all the Christmas.
To sum up, as an university student in her first year, I hardly believe educational professionals should take time to reflect if they are doing well, because for me, the answer is clearly NOT.