The calendar used by the Elves of Rivendell, and in fact the only calendar of the Elves that is known in any detail. The structure of the year (or loa) was entirely different from that found in the calendars of Men. For all practical purposes, the Elves were immortal, and so for them time seemed to pass more quickly than for mortal Men. This is reflected in their calendar, which has just six 'months' (or 'seasons') of up to seventy-two days each: specifically Tuilë, Lairë, Yávië, Quellë, Hrívë and Coirë. There were also feast-days set aside to mark the end of one year and the beginning of the next, and a series of days in the middle of the year - the Enderi - that fell at the end of Yávië or autumn.

For a tabulated summary of the Calendar of Imladris, see the entry for the Reckoning of Rivendell.