ok, this was suprising from juxt/interval

(t/new-interval (t/date "2020-01-01")
                  (t/date "2020-01-02"))
  #:tick{:beginning #time/date-time "2020-01-01T00:00", :end #time/date-time "2020-01-03T00:00"}

I didn't expect the end time to have the date of the next day

which makes using t/relation a bit tricky

The end is exclusive.

Or I think it is based on that