Generates an .ics for tricky shift work. See https://webchick.substack.com/p/using-icalendar-for-semi-predictable for background.
This script assumes you have a CSV file in the same directory called "shifts.csv" and it contains values like the following:
2021-01-19,Day
2021-02-04,Eve
Adjust accordingly!
To use it:
./shifty.sh > shifts.ics