I love this idea and will forward the suggestion to our Product Team. I see that you currently are manually creating orders. That said, I have a suggestion (this could work for synced orders too should you ever add a new store to ShippingEasy):
In ShippingEasy, the "Created Date" is defined by the date a rate quote is given. So, if you create a rule that assigns Saved Carrier Selections to your orders (this link uses Products as the rule's "IF" statement but you would likely want to use SKUs), a rate quote should be immediately applied to that order on the Orders page. This is both for when you create a manual order or the order comes into ShippingEasy via syncing. Then, no matter what method you choose to purchase your label from ShippingEasy for that order, the "Created Date" should be the date the manual order (or synced order) was added to ShippingEasy.
There are only a couple scenarios I see this not working for you:
1. With Manual orders: If a customer ordered yesterday and you manually added their order in today, the "Created Date" would show today as the date the order was created.
2. With Synced orders: If the order comes into ShippingEasy on it's automatic sync after midnight, the "Created Date" would be the day after the products were ordered by the customer.
Barring those two examples, I think this could be a great workaround for you until we offer a column that shows the date the shipment was ordered.
Thanks again for your feedback!