tolkien - How long did it take Fëanor and his sons to sail from Valinor to Beleriand?

Some sweet maps

I'll try to explain this with maps. Yes, maps. I've found them. Thanks Google.

This is the map of Tolkien's creation made by Karen Wynn Fonstadt:

In the far left, you can see Valinor. If you want to go Beleriand by sea, you have to cross Belegaer and reach Bay of Balar (most optimistic approach).

And this is the map of Beleriand:

It must have been around 19 years (solar years). Too long? Must explain.

Explanation

In The Silmarillion, there is almost no hint of a passage of time
between the departure of the Noldor from Tirion, and their arrival
in Middle-earth. The only point where the length of the journey is
mentioned is in ch. 9, Of the Flight of the Noldor, where we're told that
they had 'marched for a great while in the unmeasured night' (this
was after the Darkening of Valinor, so 'night' here just means that
they were marching in darkness).

The Noldor set out from the central regions of the World, and a very large number of them had to travel thousands of miles into the far
north. It's reasonable to assume that this journey must have taken
at least several years.

In fact, we have the Annals of Aman to give us some insight into
this matter (in Morgoth's Ring, volume 10 of The History of
Middle-earth). There, the departure of the Noldor is dated 1495,
and their arrival in Middle-earth is dated 1497. These dates are
given in Years of the Trees from their first planting, with each
Year of the Trees being equivalent to about 9½ solar years. The Flight ofthe Noldor from Aman into Middle-earth, then, took
very roughly nineteen years to complete.

Whether the journey of the Noldor was a 'flight' or a 'return' is
a matter of perspective. To the Valar, and the Elves they left
behind in Aman, the Noldor were fleeing into the dark east of the
World. To the Sindar and other Elves who had remained in the
Hither Lands, it was the return of long-sundered kin out of the
unknown west.

Also take a look at Shadowy Seas.

Also related: Nienna.

Bonus Information >> The only hint is in Quenta Silmarillion ch. 9, Of the Flight of the Noldor, where she 'cast back her grey hood'. Given that Gandalf was her student, this might (though somewhat doubtfully) have some relevance to his title, the Grey.