But doesn't it still signify their separation for the Austro-Hungarian empire? Prior to WWI, what are now the Czech Republic and Slovakia were provinces of the Austro-Hungarian empire ruled by the Hapsburgs.
Indeed it does. Quite a few Czech-Americans observe it. I wouldn't be surprised to see it drop off in the Czech Republic now, and even more in Slovakia. I find in talking to my cousins that the study of history was greatly diluted during the years they were growing up under socialism. They knew that the stuff they were being taught was heavy on B.S., but they didn't have the full scope of what was missing. Many of the history texts were revised or destroyed in these years, resulting in some gaps in what is commonly studied and known. Even well educated people will sometimes admit to rather a limited knowledge of their national history (by European standards). They are busy earning a living and raising kids, like adults all over the world. There's limited time available for going back and learning that which was missed in formal studies. I've seen other weakening in cultural and folk traditions as the Czech Republic becomes increasingly re-integrated into the European mainstream and the pace becomes more hectic.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." -Manuel II Paleologus