Add prev, current, and next month to Gravity Form select field

add-months-to-gform

var monthNames = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];

var now = new Date(),
    prev = monthNames[now.getMonth() - 1] + " " + now.getFullYear(),
    current = monthNames[now.getMonth()] + " " + now.getFullYear(),
    next = monthNames[now.getMonth() + 1]  + " " + now.getFullYear(),

    optionsField = $('.gfield_select'),
    options = [prev, current, next];

optionsField.empty();

$.each(options, function (i, option) {
  optionsField.append($('<option>', { 
      value: i,
      text: option
  }));
});