app/views/records/edit_fields/_copyright_date.html.erb
<% if f.object.multiple? key %>
<%= f.input :copyright_date, as: :multi_value, html5: true, placeholder: "Date Format YYYY",
input_html: { class: 'integer-input', min: 1900, max: 2500 } %>
<% else %>
<%= f.input :copyright_date, as: :integer, html5: true, placeholder: "Date Format YYYY",
input_html: { class: 'integer-input', min: 1900, max: 2500 } %>
<% end %>