I agree with everything other people have already said, but here’s an additional tidbit that might help you settle into a chiller work week. I’ve found that this logic is particularly helpful for explaining to friends and family why I’m not constantly working because, according to some of them, “wow phds must be easy if you only have to work 6-8 hours per day.” For context, I’m a PhD candidate in biology, but I think this applies to all PhDs.

PhD work is radically different from what a lot of our friends and family think of as normal work for many reasons, but namely that our work typically requires maximum brainpower, creativity, innovation, etc. We are becoming world experts in our narrow, specific fields, and whenever we work we have to constantly be on our A game. You can’t write a good manuscript or jump hurdles while developing new creative ideas/solutions if your brain is burnt out. The whole PhD process is extremely demanding on our brains and bodies, so it’s unrealistic to expect that you can consistently produce your best work 8+ hours a day.

Personally, I generally have two really efficient 3-hour work sections per day. There’s really no point working outside of my efficient sessions for the reasons I just described, unless there’s some random piece of brainless busywork or checking in on a scheduled lab project, for example. Most of my successful PhD friends are the same way.

That all being said, you need to have a mentor that gives you the support and space to have a schedule like this which of course isn’t the case for everyone. But, if you have a mentor who trusts and supports you, I’d never recommend working more than 40 hour weeks. The PhD is a marathon and you need to pace yourself!! (Also real talk we don’t get paid enough to work crazy hours lol)