It’s any day of any year, which means that somewhere C. S. Lewis is being misquoted in spades.
In this particular case, the misquote appears in a bad font on a trite graduation card distributed by Papyrus, which is perhaps the most trite font of all, but I digress.
Here’s the offending phrase:
Links to crystalkirgiss.com (3)
apilgriminnarnia.comA Pilgrim in Narnia - a journey through the imaginative worlds of C.S. Lewis, J.R.R. Tolkien, and the Inklings