app/assets/javascripts/trestle/i18n.js.erb
<% flatpickr_locale_conversions = { ca: "cat", el: "gr", nb: "no", vi: "vn" } %>
<% I18n.available_locales.sort.each do |locale| %>
<% Trestle.i18n_fallbacks(locale).each do |candidate| %>
<% candidate = flatpickr_locale_conversions[candidate] || candidate %>
<% require_asset("trestle/flatpickr/#{candidate}") rescue nil %>
<% end %>
<% end %>