No, there's no way that I've found to do that. In fact I don't use PHotos for my calendars. I have an external SSD with Mojave on it and use iPhoto to create books and calendars. I boot into my Mojave SSD build my book/calendar and buy. This is the setup I use:

That was I can save the item as a PDF file (hold down the Option key and click on the Buy button) and upload it to either Mimeo or PrestoPhotos for printing. Both will take iPhoto PDF files for printing. Mimeo used to be a subcontractor for Apple when Apple was profiting the printed products
If you have a backup of your older system or can install Mojave on an external SSD you can migrate your older user TM files that include iPhoto with Migration Assistant.
Otherwise it's a pain to enter each of the birthdays into the calendar manually.
