Is this possible in PHP/JavaScript?

I am making two pages.  The first one displays a picture depending on the day - so if it's January 10 2008, the displayed pic is 2008-01-10.jpg

Next, I want to make a calendar, with each day linking to the appropriate pic of the day.  However, I want to make it so it's impossible to view pics before their day, either by not making them hyperlinks, or by making it so nothing happens when they are clicked on.  Problem is, I have no clue as to how to approach this problem aside from making 365 if-else blocks.

Any ideas?

You don't need 365 if/else blocks. Only 365 ifs

if (today > Jan1st) {
  ...
  if (today > Jan2nd) {
     ...
)))))))....)))))

And so Ive fixed all your problems. And you didn't have to read SICP.