It is a good time-saving habit to look out for repetitive tasks which can be automated. Computers are, in principle, capable of repeating exactly the same calculation on different input data more accurately than any human. Despite this huge potential, software is not always built with automation in mind. Fortunately, if the software supports moving data in and out via a well-documented, non-proprietary format, we can get quite far with just a bit of our own programming.

In this post I present a Python script that automates generating my calendar for the university term, given a concise specification of events by term week. Any student or teacher at the University of Cambridge might find it useful. Get it from my sourcehut.

The problem

The University of Cambridge has a slightly obscure convention for scheduling lectures and other events: term is divided into eight weeks starting on a Thursday. (Supposedly, this was so that students could attend Sunday church services at home before making the slow journey to Cambridge and arriving in time to start studying.) Your introductory lecture might be on “Thursday, week 1”, supervisions might take place “Mondays, odd weeks”, your stress levels peak during the “week 5 blues”, lectures finish “Wednesday, week 8”, and so on. The date of any event is quoted relative to the start of term.

Before a new term begins, I receive my schedule written down by Cambridge weeks on some kind of pdf timetable. I then have to look up when exactly term starts, offset to the relevant week and weekday, and enter the events into my calendar on the correct dates. Tedious and ripe for automation.

Input file format

We need to know three pieces of information to uniquely specify a day in the Cambridge calendaring system: which term (Michaelmas, Lent, or Easter), a week number, and a day of the week. Optionally, we can add a time of day. We also need a description for what is happening on that date.

I chose the input file layout first. Each event is listed on a separate line, with the format:

$TERM $DAY_OF_WEEK $WEEK_NO [$HOURS:$MINUTES] ; $DESCRIPTION

where a semicolon separates date/time specification from the description, and the other fields are space-separated (but consecutive spaces are ignored).

Any human-readable file should allow for comments and white space. Blank lines and lines starting with # are ignored.

A date specification looks something like,

M Thu 1 ; Start of Michaelmas term

or if a time is required as well,

M Thu 1 09:00 ; First lecture

It is also useful to support recurring events on multiple weeks, or negative weeks for before term. These examples are all valid events:

M Wed -1 ; Day before lectures start
L Wed odd 15:00 ; Lent term supervisions
L Tue even 15:00 ; Other supervisions
L Fri 4-8 15:00 ; More supervisions
L Mon 1,3,6-9 15:00 ; Even more supervisions
E Thu 2,3 15:00 ; Easter term revision supervisions

As a complete example, here is a yearly calendar yearly.dat with dates for admissions interviews and MEng fourth-year project administration:

# Admissions

M Mon 9 ; Interviews start
M Fri 11 ; Interview end

# Fourth-year projects

M Wed 1 ; 4YP hazard form
M Fri 5 ; 4YP progress form
M Thu 7 ; 4YP presentations
M Wed 8 ; 4YP presentation feedback
M Fri 9 ; 4YP progress form

L Thu 1 ; 4YP TMR hand in
L Thu 5 ; 4YP TMR mark form
L Fri 5 ; 4YP progress form
L Fri 9 ; 4YP progress form

E Mon -1; 4YP proposals
E Fri 3 ; 4YP preallocation
E Wed 5 ; 4YP report hand in
E Thu 6 ; 4YP presentations start
E Fri 7 ; 4YP planning form

Usage

I will not go into the detail of the coding – it is quite basic:

• Input the academic year of interest as a command-line option;
• Parse an event file line-by-line, converting the formatted data into a tuple of indices for (term, week_no, day_of_week) and an optional time;
• The University Statutes and Ordinances do not specify a general rule for determining when term starts, instead giving a table up to 2030. So I thought the best I could do was hard-code the start dates of every term and update in eight years time;
• Offset from the term start date by the required number of weeks and days to give a datetime object for each event;
• Use the icalendar library to generate an ics file with our events in it.

To generate an ics from the yearly calendar input data given above, for the next academic year 2022/23,

$ python uccalgen.py yearly.dat yearly.ics 2022

The resulting yearly.ics can be imported into any standards-compliant calendar application.

I hope that others might find this script useful. You can get the code from my sourcehut. There are a few tests, and I use it myself, so I have a reasonable degree of confidence in a lack bugs!