Days of Bliss

The Days of Bliss or the Noontide of Valinor was the time when the Two Trees blossomed in Valinor, also known as the Years of the Trees. This period begun at the Opening Hour, in the First Day, when Telperion first started to bloom. It was also the beginning of the Count of Time.

Sources: The Silmarillion, ch. 1; also mentioned at the beginning of ch. 6: "The love of Finwë and Míriel was great and glad, for it began in the Blessed Realm in the Days of Bliss"; and at the end of ch. 23: "and he [Ulmo] called on them to forgive them - - - and win back the Silmarils, wherein alone now bloomed the light of the Days of Bliss when the Two Trees still shone in Valinor".