elm-wareki A convert date to wareki for elm program. Usage > import Wareki > import Time > Wareki.toNengoFromPosix <| Time.millisToPosix 1599909981000 Ok "令和" : Result String String > Wareki.toWarekiFromIsoString "2020-09-03" ] "令和2年9月3日" : String Reference https://korban.net/posts/elm/2018-10-02-basic-steps-publish-package-elm-19/ https://www.benricho.org/nenrei/sei-wa-conv.html