Behold the homepage of Anamnesis, the bulletin of the liturgical commission of the Polish Bishops' conference. ("Anamnsis" at the top of the page is simply a typo, it is of course simply the Greek word for the memorial sacrifice of Num 10:10, alluded to in Lk 22:19 and 1 Cor 11:25).
In 2004 I discovered that the editio typica tertia of Missale Romanum included some new saints in the calendar. This is the Universal Calendar, also called the General Calendar. Local churches at the diocesan or national level are expected to modify the calendar usually by adding local saints or sometimes by increasing the importance of the celebration.
This being the Missal – to be used at Mass – it does not have texts for the Liturgy of the Hours (the "Divine Office", often simply just the "Office"). Using as a search text the collect (which is the same as the concluding prayer in the Office) of one of the additions to the calendar, I discovered that the Polish Bishops had put the Latin texts of additions to the Divine Office online. Additions to the liturgical books are published in the journal of the Congregation for Divine Worship and Discipline of the Sacraments, Notitiae which was not, and is not, published online. However all the decrees from the Congregation pertaining to the Universal Church, including such additions to the calendar are, as a matter of course, published in Latin in Anamnesis.
Go to Komisja Kultu Bożego i Dyscypliny Sakramentów Episkopatu Polski (that takes you to the Anamnesis page). Look at the column on the left hand side of the screen. Indeksy numerów 1-26 takes you to indexes for the first 26 issues. These are not very helpful as they are not hyperlinked. Issues 1-7 are not online. Click on Numer 8 to find out why. "Od Redakcij" means "From the Editor", this issue was published on 1st November 1996. When I refer to the "Editorial" of a given issue of Anamnesis in what follows, I mean whatever you read by clicking on "Od Redakcij".
Also in issue 8, "Przygotowanie do wprowadzania katecumenatu w diecezjach - materiały z Sympozjum Katechumenalnego Sandomierz - 16 i 17 września 1996" is the proceedings (I guess) of a conference held on and 17th September on the history of the rites of initiation. "Informacje" means "Information". "Spis treści means "table of contents". Click on that and you will get links to two pdfs, one of which is in dear old English, and we read:
After publication of seven issues of Anamnesis (1994-1996) – Bulletin of the Polish Episcopal Commission for Divine Worship and the Discipline of the Sacraments which was designed for the Polish Bishops – a new edition of Anamnesis is being started which is addressed to people responsible for liturgy and liturgical pastoral care in the Church in Poland, anxious for more intense renewal of the Church by more conscious, active and deepened participation of all the Christians in the Liturgy. The editorial design is to create a meeting forum for the two directions of the liturgical renewal: the one “from above” (institutional) and one “from below”.The editorials are often undated so it is hard to determine the frequency. The editorial for issue 20 is dated 28th November 1999.
The important thing for our purposes (well, OK, my purposes) is what is usually the first section of an issue of Anamnesis: Dokumenty Stolicy Apostolskiej - Documents of the Apostolic See. These are typically decress from the Congregation DWDS. Number 22 contains the authorisation for the Polish texts for the office of Blessed Pius of Pietrelcina (as he then was, i.e. Padre Pio). The decree from the Vatican is dated 26th November 1999, but the editorial is dated 1st June 2000. The series is clearly not regular since issue 26 has an editorial dated 2nd June 2001 and there is clearly a lag between the promulgation of the decree and its publication in Anamnesis. Issue 31 has an editorial dated 18th May 2002 but its URL suggests that it has been linked to by mistake because the filename for the PDF is "Anamnesis30-0aRed" which is also what you get when you click through from "Od Redakcij" for issue 30. Issue 32 has an editorial dated November 16th 2002.
I labour over Anamnesis 31 because the second pdf among the Dokumenty Stolicy Apostolskiej in that issue is Dodatki do Liturgii Godzin - Additiones ad Liturgiam Horarum. This is the text in Latin of the additions to the Liturgy of the Hours made with the 3rd edition of Missale Romanum by a decree of the Congregation dated 18th December 2001. The next issue (32) contains the texts for the Mass and Office of Padre Pio decreed by the Congregation on 26th June 2002. Finally on 12th February 2004 the Congregation published texts for the Liturgies of St Juan Diego Cuauhtlotoatzin and Our Lady of Guadalupe.
So far as I can tell there have been no additions to the Universal Calendar since 2004. Granted you have to wrestle with Polish but Anamnesis is a useful resource.