The event
The first Elves awake at Cuiviénen by the light of the stars.
On the dating
The awakening is placed at the transition from the Years of the Trees to the First Age; calendars differ.
Consequences
The Valar resolve to protect the Elves; the Great Journey and the sundering of the Elves begin.
Sources
The Silmarillion · 1977
Posthumously edited. Contains the Ainulindalë, Valaquenta, Quenta Silmarillion, Akallabêth and Of the Rings of Power.