Today is Good Friday, the day on which Christ was crucified for our sins, and if you know anything about Tolkien, you probably know that it is also the anniversary of the day when Frodo and Sam made it to Mount Doom and destroyed the Ring. It was never a coincidence that Tolkien chose March 25 for this important date in Middle-Earth history (just as it was no coincidence that he chose December 25 as the date the Fellowship set out from Rivendell).
You see, there is a very old tradition that states that the original Good Friday took place on March 25. I’ve heard conflicting reports on whether or not that tradition is accurate, but the important point is that there is a good chance Tolkien had heard of it, him being Catholic and all. Making the day when the power of the Ring is forever broken the same day as when Christ broke the power of sin and death would have been an extremely powerful parallel for a story already rich with Catholic symbols and parallels (there’s a brief mention of Original Sin–“It was fitting that Isildur’s heir should labor to repair Isildur’s fault”–lembas means “life-bread” or “bread of life”, which is a common title for the Eucharist, etc.).
Of course, March 25 is also the Feast of the Annunciation, which is more commonly known, so it’s also possible that Tolkien chose that date for the Ring’s destruction to honor the Annunciation, in which case I have officially lost my mind. But even if I am wrong about why he used March 25, it is still a fascinating parallel to ponder.