Avoid fixed schedule with many meetings.
Time management for PhD student, my experience as a computer systems graduate student.
Time management is one of the most important skills a PhD student can learn during his or her PhD. Yet I believe this is the most important skill you can learn because you have to finish in a limited time. You are literally going to chase time the entire program, and consuming this resource judiciously is really, really, really important.
As a novice Ph.D. student, I was too excited and allowed my schedule to include many meetings over a single week. I had multiple meetings each day, and since I was collaborating with multiple institutions from Singapore to the United States, I had to cover a large span of time zones. I believe this is a big mistake, and every Ph.D. student should avoid such a schedule.
I was collaborating on projects based in Singapore. Therefore, I had to meet them in the morning (London UK time), and then I had to meet with some other folks in Pacific time in the afternoon, like 7 pm or 6 pm for some other projects. This was really draining. It is really important to pick collaborators in the same time zone anyway. Though my friends were so kind and tried to be flexible as much as possible. Actually UK is really well positioned in terms of timezone to be working with people in the States, Europe, and Southeast Asia. But this is still not the point of this blog post.
As a computer systems PhD student, I really need long blocks of time in my schedule to be able to read papers deeply and implement or investigate large codebases. As an example, when you are investigating Linux kernel codebase (probably the largest open source code base humans managed to build). It really takes time to pull the strings and come up with the right mental model of software in order to just understand where you are in the code, let alone to understand how it works.
Further, reading a single paper may need a lot of time to just get past the introduction. Now, the point of reading a paper is not just to say I read it; you really want to walk in the footsteps of authors and think about what they thought when writing and reason every single sentence. That is basically how you confidently can say you have understood a paper.
Ph.D. students need quite high levels of focus to be able to take steps forward in various tasks such as reading papers, moving through codebases, or even implementing solutions. However, having multiple meetings during the day can significantly reduce your focus, which eventually results in lower productivity (recall that you are chasing time, and every second counts).
The main issue is random meetings over a day, which distracts you from what you are doing. These meetings can be related to any project and can take from 30 minutes to hours. They can completely wipe out your memory, and this is highly detrimental to the pace of your work. Maybe working in this fashion for a couple of weeks is OK, but for years or months is a big mistake.
A desirable scenario would be having your meeting packed in one day and you just keep your flexibility for the entire week. I also suggest avoiding setting fixed meetings every week. You do not need a meeting unless you need a meeting. Doing a PhD is one of the most flexible jobs you can ever take. You work wherever you want, on whatever you want, and whenever you want. If you keep your schedule fixed and filled with meetings with people, then you will not have the flexibility that is important.
What does it mean to have flexibility? I think it is quite nice to have as many days without meeting as possible. This helps to plan a day without interruption, improving my productivity. This might be a little adjustment, but experience says these little adjustments can yield a lot in the long run. This is usually the case because PhD programs are quite long, and they can span over 3-6 years, depending on your major and country of study.