I have a couple of situations: one where I will be having events posted on my website, and I want to be able to program the button for the event to expire 24 hours beforehand. The other is for a special that I will be running on a product, where the price for that product will go up after a certain date, so I want that button to be able to "expire" as well. How can I do that?
PayPal's Website Payments Standard does not have any built in features or options to do what you have in mind. You would need to develop some custom scripting on your web page or site to manage the logic. If coding your own stuff is something you don't want to deal with, you can always see the assistance of a Developer. Another option would be to use a 3rd party service, for example this one is for events.
