Best of luck!
I think it really depends on your personality and workload. Some people like to take 1-2 h everyday to unwind and relax, while others take a full day off in the weekends. Some people prefer to give themselves a treat after completing a major task/goal etc. The key is you need to figure out what works best for you in order to finish your work on time and achieve your goals.
I agree with previous answers, a good way to start is to determine your priorities and choose the recreational activities wisely (i.e. choose the ones that really help you relax and have fun (e.g. spending time with family and friends, hobbies, sports, volunteer work) rather than trying to attend every single event). I always find it useful to have a weekly schedule with some flexibility to account for unforeseen events or in case something takes longer than expected.
Wishing you all the best!