Create a file .env like this
FEIDE_USERNAME=mcmcesen
FEIDE_PWD=passordet-ditt
In days.js you can add booking times to every day. For a specific day, simple create a list of time slots you want to book. Every time slot contains a startHourString and endHourString (see the file for example).
This always books E3-107, but hit a PR if you want to make it more general.