Tolkien's final First Age timeline

[Arvegil145]

@Huinesoron: another late (written on paper dated to 1968, text itself probably even later) text from the NoME that might just be the latest conception about the duration of the First Age that Tolkien wrote:

The legends speak of a sojourn of many years and long debates before the Vanyar and Noldor after long exploration began the crossing “by the pass under the Red Mountain”. They were followed by some two-thirds of the Teleri. A third, mainly belonging to the folk of Olwë, had become during the delay well contented, and remained behind. There was no contact between these Silvan Elves and the Grey Elves, the Sindar, who in the event also remained in Middle-earth and never crossed the Great Sea, until the Second Age and the ruin of Beleriand. In Mannish terms that was a time as long maybe as all the years that now lie between us and the War of the Ring.

- The Nature of Middle-earth, 'Silvan Elves & Silvan Elvish', Text 1, pp. 357-8


So, even if you assume the earlier, conservative 1958 figure of c. 6,000 years (from the Letters) - that still leaves 6,000 years between the sundering of the Nandor and the end of the War of Wrath.

If you assume the later, 1960 figure from the NoME - that's c. 9,250 years.

In any case, this expands the timeline massively.