Every PhD is a different, not only in terms of the research you do but also the environment in which you do it.
Some of the variation is a natural consequence of national culture; doing a PhD in the UK is quite different to doing one in the Japan, for example, simply because the cultures are quite different. So if you go to work in a different culture, you need to be aware of the local customs and expectations.
But beyond national variation, there is also great variation within the borders of individual nations and institutions. You need to be aware of the local academic culture, customs and expectations within your specific research group.
Local academic culture
In some research groups, you are expected to be in the lab before 9am every day. In some groups, you are expected to work weekends. In others, arriving late is OK if you leave later. Perhaps nobody cares what hours you work as long as you get the job done.
When I moved to France for my first postdoc, I wasn’t legally allowed to work more than 35 hours per week. When I moved to Spain, my boss told me that if I took a day’s holiday I should come in at the weekends to make up for the lost time. Similar national cultures, but very different local customs.
Know what’s expected of you
Different cultures suit different people. Some thrive in a highly-competitive environment and love to work every hour of every day, some thrive in a more relaxed atmosphere.
I knew one student who signed up for a master’s course, but quit immediately on discovering that there were classes on Saturdays. She wasn’t willing to give up the weekend, so went somewhere else. You have to know what is expected of you so you can make a clear decision as to what you are willing to do and whether the local culture suits you.
Know what you can expect from others
Every supervisor is different in terms of the amount and type of support they give their students.
Some are very hands-off and leave you to get on with the work, others are involved in everything. Both approaches have their advantages and disadvantages, but you have to know what you can expect from them. Will you see them once a week? Or once per year?
Think about the kind of support you want from a supervisor and ask them what you can expect. Then you can decide whether they are the right supervisor for you.
If you don’t know what is expected of you, find out.
If you don’t know what you can expect from others, ask.
If you don’t know what you are willing to do, decide.