My research–teaching–service split, 2019–2021

The job of a professor is traditionally split into three categories: research, teaching, and service. For example, I'm evaluated for promotion in those three categories. What exactly goes in each is sometimes fuzzy, but roughly:

Research: Running experiments, analyzing data, writing code, reading papers, writing papers, submitting grant proposals, managing grants, supervising research students, meeting with collaborators, attending or giving research talks.
Teaching: Preparing course materials, teaching the actual classes, holding office hours, grading, answering student emails, the less researchy parts of student supervision/mentoring, and teaching-related administration (waitlists, withdrawals, etc.).
Service: Serving on department/college/university committees, general administrative work, filling out forms, faculty meetings, reviewing papers, organizing conferences, and so on. Often split further into "internal" service to the university versus "external" service to one's field.

Some faculty jobs officially specify the expected split between these categories. For example, when I worked in Denmark, my contract specified 40% research, 40% teaching, 20% service. My current contract doesn't specify, beyond that my normal teaching load is two courses a semester, and I'm expected to do all three categories. In practice my understanding is that research is weighted the most of the three for purposes of tenure and promotion, but that isn't formalized. Regardless, I'm curious what my actual split has turned out to be.

I started my current tenure-track job in January 2019, and have been keeping an approximate time log since then, noting how many hours I spend each day in a more specific set of categories like "course prep", "paper writing", "office hours", etc. Below I aggregate those categories into the traditional teaching/research/service split, broken out by semesters and inter-semester breaks. I'm defining a "semester" for this purpose as starting one week before the first day of classes, and ending on the day that grades are due. For our academic calendar, that makes semesters a little over 4 months long.

Below are the results for my first three full years here:

Year	Period	Research	Teaching	Service
2019	Spring semester	29%	41%	30%
2019	Fall semester	39%	24%	36%
2019	Summer/Winter breaks	58%	5%	37%
2020	Spring semester	27%	39%	34%
2020	Fall semester	26%	44%	30%
2020	Summer/Winter breaks	58%	12%	30%
2021	Spring semester	43%	33%	24%
2021	Fall semester	28%	38%	34%
2021	Summer/Winter breaks	68%	3%	29%

Unsurprisingly, teaching is concentrated within the academic year, and typically takes 35-40% of my time, with the exception of Fall 2019, when I had a 1-course teaching reduction as a new faculty member. Service averages around 30%, without any real change between the academic year and breaks. Research varies inversely with teaching, constituting the majority of my time outside of the academic year, and dropping to 25-40% within the academic year, with a decent amount of variability between semesters depending on how much time other obligations leave for it.