The Four Seasons
The Ember days, which fall on a Wednesday, Friday, and Saturday of the same week, occur in conjunction with the four natural seasons of the year. Autumn brings the September Embertide, also called the Michaelmas Embertide because of their proximity to the Feast of St. Michael on September 29. Winter, on the other hand, brings the December Embertide during the third week of Advent, and spring brings the Lenten Embertide after the first Sunday of Lent. Finally, summer heralds the Whitsun Embertide, which takes place within the Octave of Pentecost.
In the 1962 Missal the Ember days are ranked as ferias of the second class, weekdays of special importance that even supersede certain saints’ feasts. Each day has its own proper Mass, all of which are quite old. One proof of their antiquity is that they are one of the few days in the Gregorian rite (as the ’62 Missal is now being called) which has as many as five lessons from the Old Testament in addition to the Epistle reading, an ancient arrangement indeed.
Fasting and partial abstinence during the Ember days were also enjoined on the faithful from time immemorial until the 1960s. It is the association of fasting and penance with the Embertides that led some to think that their peculiar name has something to do with smoldering ash, or embers. But the English name is probably derived from their Latin title, Quatuor Temporibus, or The Four Seasons.
Source: Michael P. Foley/Rotate Caeli.