Ember Days, the days of fasting and abstinence at the beginning of each of the seasons, are ancient in origin. According to the Catholic Encyclopaedia:
"The 'Liber Pontificalis' ascribes to Pope Callistus (217-222) a law ordering the fast, but probably it is older. Leo the Great (440-461) considers it an Apostolic institution. When the fourth season was added cannot be ascertained, but Gelasius (492-496) speaks of all four. This pope also permitted the conferring of priesthood and deaconship on the Saturdays of ember week - these were formerly given only at Easter. Before Gelasius the ember days were known only in Rome, but after his time their observance spread. They were brought into England by St. Augustine."
(Rogation Days are also an ancient tradition:
"Days of prayer, and formerly also of fasting, instituted by the Church to appease God's anger at man's transgressions, to ask protection in calamities, and to obtain a good and bountiful harvest.")
Few Catholics under the age of 70 (other than those who regularly attend the EF) will know what these are, as they were done away with. Strange to say, this was not by Bugnini and his colleagues, although they were happy to mess with them. Bugnini writes:
"The Ember Days are to be celebrated at times and on days to be determined by the episcopal conferences, provided that they are in harmony with the seasons and thus truly correspond to the purposes for which they were established."
Pope Paul told Bugnini that he would insist that any periods which replaced the then-existing Ember Days should be carefully determined by the episcopal conferences and that should also be days of prayer for vocations to the priesthood and religious life.
So where are the Ember Days?
According to the Catholic Bishops' Conference of England and Wales:
"Amongst these other celebrations, from the earliest times have been the rogation and ember days, days of prayer for particular need or in thanksgiving for particular blessings of the Lord. Since 1972 the Bishops’ Conference of England and Wales has preferred to drop all distinction between ember and rogation days, and to speak simply of Days of special prayer.
In 1972 six such days were introduced but in the years which followed the number of such days increased to such an extent that they risked intruding on the celebration of the liturgical year, and especially on the celebration of the Lord’s Day on Sundays. Subsequently the Bishops’ Conference concluded that from Advent 1996 these Days of special prayer be subsumed into and replaced by a Cycle of Prayer.
The Cycle of Prayer seeks to preserve the integrity of the Sunday liturgy, without losing sight of the importance of being united with the universal or local Church in praying and working for important intentions. It seeks to do this be encouraging the faithful to pray for the intentions set out in the Cycle in their personal prayers throughout the period specified, and not only at Mass on a particular day.
The Cycle of Prayer is based on a division of the year into six periods, three of these being the principal liturgical seasons of Advent/Christmas; Lent and Easter and the other three periods being divisions of Ordinary Time, namely Winter, Summer and Autumn."
So apart from losing their initial capital letters, the Ember and Rogation Days were merged, were stripped of their penitential character, were separated from their association with the seasons and harvests, were moved from their ancient, perhaps even apostolic, dates, and were then abolished and replaced by a "Cycle of Prayer", which was apparently instituted in 1996, and which is important enough to have a page dedicated to it by the CBCEW Liturgy Office (here), and which I, for one, have never heard of before.
This is how Nu-Church is constructed. Take something venerable and say how important it is: so important that it needs to be specially adapted for every country and territory; and if the adaptation kills it off, well: that's how traditions evolve, isn't it. And if what replaces the venerable something ends up being neglected and ignored by everybody, it must be that the venerable something needed to have been abolished anyway.