app/assets/javascripts/jquery.ui.datepicker-customDefaults.js.coffee
jQuery.datepicker.setDefaults
changeYear: true
changeMonth: true
yearRange: '1992:+0' # no hay registros anteriores a 1992
# Fix issue with hardcoded format in Active Admin
jQuery ->
$(".datepicker")
.datepicker("option", "dateFormat", "dd/mm/yy")