I didn't know that -- I thought the changes were of the Church. So am I justified in continuing to celebrate St. Francis de Sales' day on January 29, instead of observing it on the 24th, which doesn't feel right? (I went to a grammar school named for St. Francis de Sales, so we got it off -- I'll always think of it as on the 29th!)
Some of the changes in the calendar were made throughout the entire Church. However, national bishops conferences apparently have the power to make changes on their own for what they claim are "pastoral" reasons. This is why in the US, most holy days of obligation have either been suppressed or moved to the nearest Sunday, etc. Presumably the good bishops think either their clergy or their laity are too lazy to get to Mass at any other time.
But since individual bishops can also make these changes for their particular diocese, even that is not uniform.
For some reason, a liturgical season they have particularly chosen to mess up is Christmas. They've completely broken the cycle and the unity of the events after the Nativity itself.
Some of them defend this by pointing out that the Eastern rites celebrate these events on a totally different calendar, but to my mind, that really doesn't matter.
The celebration of the Ephiphany on Jan. 6 dates way back and was very much entrenched in Western cultural practices - by the year 380, for example, it was a "legal holiday" in Spain, a day when no business was done (Christmas had at one time been celebrated on Jan. 6th as well, but by that time had been moved to Dec. 25). While it still remains on the 6th in many countries, the US bishops for some reason wanted to break with that, make the whole feast unimportant, and destroy the cultural practices grown up around it. Much of Vatican II was, in my opinion, directed at breaking up Catholic culture, a large part of which revolved around the liturgical cycle. The "reformers" succeeded abundantly, alas, particularly in the US.