Use Cron Jobs to run tests on a fixed/predictable interval?

[Nelson]

https://docs.travis-ci.com/user/cron-jobs

Just spotted this feature but it was released in 2016:
https://blog.travis-ci.com/2016-12-06-the-crons-are-here

This could be useful for projects which we don't expect to "break"
but we need to run tests periodically to ensure they are working as expected.