Thanks for reaching out and bringing this to our attention, JimmB.
The recurring transactions feature in QuickBooks Online (QBO) can help save time by automating transactions instead of inputting them manually. Right now, when creating a template, you can't set it to before today's date because it's a template for the future transaction. That is why you've got a prompt message about "The recurring start date can’t be before today".
In the meantime, you can copy the Journal entry created so that there's no need for you to repeat in entering the same information. All you have to do is to change the date.
I can see how this feature would be beneficial to you and other businesses. In the meantime, I encourage you to star our blog to keep up with any product updates or improvements on the online version: QuickBooks Online Blog.
For more information about recurring transactions, see below articles:
If there's anything else you need help with, let me know by adding a comment. I'm more than happy to assist you. Have a great day!