Advent Ember Days for 2021 are December 15 Wednesday, 17 Friday, and 18 Saturday.
These are super-ancient special penitential days near each equinox and each solstice.
There are changes in the TLM, with particular note on the numbers of readings, graduals, tracts (with no Alleluias) and prayers:
two readings from Isaiah then the Gospel on Wednesday
one reading from Isaiah then the Gospel on Friday
fully four readings from Isaiah, then from Daniel, then Daniel’s hymn!, then one from Saint Paul, then the Gospel on Saturday
Rules are said to have been fasting and abstinence on Friday (no meat, one full meal and two that don’t equal even one meal) and fasting and partial abstinence on Wednesday and Friday, the difference being meat can be included in the main meals on those days.
These penitential rules are no longer obligatory as the Canon Law promulgated in whatever epoch binds the person directly regardless of any change in the Liturgy. The present Canon Law binds those assisting at the Liturgy either of the Ancient Rite or the Novus Ordo. The present Canon Law has nothing whatsoever about Ember Days. Fasting and abstinence for the Church, for vocations, is laudatory.
The Ancient Rite is being offered in the parish church today, as always, as officially scheduled, as always, and by the Pastor, as always, who is myself. And this is all still regular in these continuing days of study and consideration of Traditionis custodes, which we’re all hoping will be fully implemented according to the standing universal law of the Church, Canon Law, specifically Canon 87, which has it that if any mere prescription is odious to the faithful the bishop can dispense from that prescription, proscribing its effects, thus aiding the cura animarum, the salvation of souls. This is not denying that there is such a motu proprio of Pope Francis. It’s just implementing it in a regular fashion, fully according to the law of the Church, with a view to the salvation of souls.
The “fiddleback” vestment above was made for me using discarded vestments of the Sanctuaries of Our Lady of Lourdes when it was all the rage to throw everything away. The “decal”, with heavy gold embroidery, was surely given by Pope Pius IX himself. I rejoice in this. Long time readers know of my particular connection to biblical aspects of the Immaculate Conception, and also of my being able, as a “permanent chaplain” to reintroduce the Ancient Liturgy back into the Sanctuaries after so many decades of violence against it.