A full-time job in Hungary means 40 hours of work a week. Most people work 8 hours a day, 5 days a week. There is also an option of working time banking, where 16 x 40 hours can be spread over 16 weeks. However, an employee still cannot work more than 12 hours a day and 48 hours a week – at least for the same employer.
In their free time, employees do whatever they want. This means they can also take on a side job, where the same restrictions will apply. Neither employer is required to consider how much you work for the other as long as the extra working hours do not affect your performance. However, if your performance starts to deteriorate due to the extra strain, the double employment cannot continue, and you will have to choose – unless one of your employers makes the choice for you and terminates your employment.
As a result, it is your responsibility as an employee not to take on a workload that is physically not sustainable for you.