What are the working hours per week for full time PhD students in Germany? Also, how many holidays are granted in a year? How is the work-life balance for full time PhD students? Thanks!
You are typically paid for 50 or 65% to do work on some project, but that just means that the university graciously allows you to write your dissertation unpaid in the remaining 50 or 35%.
How much you really spent is hugely dependent on the discipline, the department, the advisor, and yourself. The best case scenario would be when there is a huge overlap between the project and your dissertation, both the department and the advisor are very supportive, and you are very disciplined and get a lot of work done in a short period of time. This does happen, but not everybody is that lucky.
Sorry, but there is not definitive answer to this question as it varies a lot between fields and even between different workgroups and then even between different students in a workgroup.
While "working fulltime" usually means 100% (which is 39.2h/week in my state but could be different in others), you may get a contract between 50% and 100% (I've heard about 16% contracts, but can not confirm this). If you are expected to be in the office for the whole time or not depends. Also, you may have teaching duties or not. You may have to work on a project which is not directly related to you thesis or not. The holidays depend on the state and on your age (or work experience) but in general there is plenty of holiday in Germany (should be somewhere between 25 and 30 days, so five to six weeks). The work-life-balance varies even more. You'll hear very different stories from "working my xxx of for a couple of years" to "had the best time of my life and managed to make great friends and learn another language"