@rende11 @danvingo yes t/inst is fn to get platform date.
for the interval calc, tick can do this with fns in the interval ns. still alpha.
(require '[tick.alpha.interval :as t.i])
(t.i/contains? (t.i/new-interval (t/date "2020-01-01") (t/date "2022-01-01")) (t/date "2021-01-01"))
there are some nice docs about intervals, see https://juxt.github.io/tick/#_comparison_4 . also see t/i/relation as a more general alternative to contains?