There is an extensive database (centuries of data)
….with strikes in The Netherlands and all kind of interesting details. I have chosen a subset of 2017 (also for training). I keep it simple (being not experienced at all) and only selected the number of strikes over one year. Not surprisingly the number of strikes (often organised by trade unions) shows a dip in our summer season. Holidays are respected (?).
Look for yourself
https://www.datawrapper.de/_/BxhbH/
The IISG in Amsterdam is a fabulous organisation and I may suggest everybody to take a look for data
https://iisg.amsterdam/en/data/linked-open-data
Links
https://iisg.amsterdam/en/data/datasets
https://www.kccourses.org/