28. říjen - Wikipedie, otevřená encyklopedie
# Státní svátek: Den vzniku samostatného československého státu
# Socialistický kalendář:

* Vyhlášení samostatnosti Čechů a Slováků (1918)
* Den znárodnění (1945) – významný den Československé socialistické republiky
* Schválení zákona o československé federaci (1968)

As this short extract from Czech Wikipedia shows, the 28th of October has played a significant role in recent Czech history. These days it is a státní svátek - meaning a day off work (unless it falls on a weekend) - in memory of the 1918 founding of Czechoslovakia (dissolved in 1939 and then again in 1993) and gaining independence of the crumbling Austrian Hungarian Empire (perceived partly as German).

During the 'communist' regime the day was also celebrated as a (re)union of Czechs and Slovaks (after 1000 years of separation since the Great Moravian Empire). And the date was chosen for other significant events:

First in 1945 to nationalize (znárodnit) big industries and then in 1968 to enact Czechoslovakia as a federal state.