[William Cloud Hicklin]

Well, not entirely.

The issue at the Pelennor was not that the Earth had stopped its daily rotation - Sauron couldn't do that! - but rather that the huge overcast of smoke and fume that Sauron created from Mt Doom, the Great Darkness, was blown away by "a wind from the sea"- the same SW wind which also enabled Aragorn's fleet to hoist sail and reach the battle in time. The first hint of this was of course that sharp-sensed rooster which crowed as the Black King was entering the gates.

Tolkien was rarely explicit about any sort of supernatural intervention- at most he would make cryptic statements like "chance, if chance it be" or "chance, as it is called in Middle-earth." Yet it's not really disputed that Eru somehow manipulated Bilbo's finding of the Ring, and in his letters Tolkien straight up says that Eru's finger saved the day, and the world, at the Sammth Naur when Frodo failed.

But as to the Valar? Who knows what they can affect, even with Valinor removed from this reality (but still connected by the Straight Road)? A great wind from the sea which was absolutely exactly what the free peoples needed implies Manwe and Ulmo having something to do with it, and the northern gale that rushed the Great Eagles to the Black Gate and Orodruin- well, both wind and eagles have Manwe's fingerprints all over them.

(NB: whether the Valar can affect things or not, apparently it's believed in Gondor, since the Rangers appeal to them to turn aside the rampaging Mumak)