Oh, boy, Murray! Thank you for bringing your great question to planDisney! I love where your head is at. I'm always game for a last-minute visit to the Happiest Place on Earth - let's go!
The short answer to your question is, yes, if there are
theme park reservations available for the date that you're wishing for, you can absolutely purchase tickets to Disneyland anytime, even up to the day-of, either at the main entrance ticket booth or on the
Disneyland website.
However, even though it is possible to purchase tickets to Disneyland with only a day's notice, I wouldn't recommend it, especially if you have your heart set on a certain day, as park reservations are limited in number. If you're worried that you may not be able to visit on the date you purchase your ticket for, there is the ability to reschedule your park reservation and ticket date, within the generous expiration window and subject to reservation availability.
Quick tip: When you're ready to purchase your tickets and make your park reservation (which you can do both at once), if you don't see availability for the park you want to visit, try changing from a One Park Per Day ticket to a
Park Hopper ticket, as different ticket types may have different availability.
Sending pixie dust for all your ticket wishes to come true, Murray, and that you'll be on your way to the magic very soon!
McCayla