How Long Does it Take to Get to Valinor?

[Galadriel55]

I'd say that the journey takes about a day.

And the ship went out into the High Sea and passed on into the West, until at last on a night of rain Frodo smelled a sweet fragnance on the air and heard the sound of singing that came over the water. And then it seemed to him that as in his dream in the house of Bombadil, the grey rain-cutrain turned all to silver glass and was rolled back, and he beheld white shores and beyond them a far green country under a swift sunrise.
But to Sam the evening deepened to darkness as he stood at the Haven...

The Grey Havens

I think that although it says on a night of rain, it means the night. Frodo left onthe morning of one day and arrived in Valinor the morning of the next day. If it wasn't for the paragraph describing Sam, I'd also say that it took Frodo a few days/weeks to get there. However, the way Tolkien compares what Sam and Frodo see, it seems like he's talking about the same night. It wouldn't make sense to say that Sam didn't see something on the first night that happened on the fifth, for example. Of course he wouldn't see something that hasn't yet happened. However, I think that the reason for Tolkien to write that is because he wanted to emphasize the separation between both Frodo and Sam, as well as ME and Valinor. It really depends on how you look at it.