<% v = !period_field.new_record? ? format_date(period_field.period_from, column.date_format, true) : "" %>
<%= f.text_field :period_from, :value => v, :placeholder => column.date_format.upcase, :data => {:format => (column.date_format == "yyyy" ? "yyyy/MM" : column.date_format)}, :class => "input-small" %>