A person must consider one thing that he has to work as long as he lives. That is why he should not work in a way that can cause great harm to his health. If you work on holidays, you can get 2 times or more of the basic salary. And this is why there are some people who cannot control their greed. They give more priority to money than taking care of their health. Every person should give time to his family even after work. When someone can use 1 day of time properly with his family after working continuously, then he remains spontaneous. This time is certainly important for a person, especially for his working life.
In my opinion, you shouldn't work on weekends and should have time to relax your mind and body. Even if you work in those days, better work for very little time and spend quality time with your family, friends and on entertainment. There is no point to keep working 24/7 or all days in the week only to make more money. If you do so, if will have a bad impact on your health.
As an example, I know my very close relative who was working in a 9-5 job and then he also got another part time Job and in order to manage both he got very little time to be free from work. What happened after few weeks of extra burden, he started to get ill often and even complained about headache often. Eventually, he had to leave that extra work.