https://ruby-doc.org/stdlib-2.1.1/libdoc/date/rdoc/Date.html#method-c-today

Date.today is a ruby core class and method which creates a date object of the current date.

Great topic. Will add to my TODO list.

Can you post the JS and Routes file?

With a nested routes like that,

get_barcode_ticket_orders POST   /tickets/:ticket_id/orders/get_barcode(.:format) orders#get_barcode

You would need to also pass the parameter ticket_id into the data hash.  Is the ticket_id available at this point? If so, you could pass it into a data attribute and access it in the JS. Otherwise, you may want to reconsider the routes to look something like this (or similar):

resources :tickets do
  resources :orders
end
post '/orders/get_barcode',  as: :get_barcode, controller: :orders, action: :get_barcode
# get_barcode POST   /orders/get_barcode(.:format)         orders#get_barcode

Since you don't have the ticket_id, it's not a valid route.

In your HTML, if the ticket_id is available and you're already displaying it somewhere then you can create a data attribute like

<%= tag :div, id: 'some_name', data: { 'ticket-id': @ticket.id } %>

You can access the value of the ticket's id in jQuery like

var ticket_id = $('#some_name').data('ticket-id');

And then in the AJAX POST

data: { ticket_id: ticket_id, upc: code }