We do allow orders to be placed despite being on back order. You should be able to see whether your item is on back-order by seeing whether there is a “back-order” tag on the product page. We do our best to update this list as often as possible along with estimated stock dates. At this time you will not get a message notifying you that you selected a back ordered item, so confirmation email doesn't necessarily mean in stock.
Our team is working hard to keep up with order demand, as all watches are currently being assembled to order in the USA. There is a back-order list, and your watch be assembled and shipped 10-14 business days from order date.