If you are searching Hungarian resources, János offers an interesting selection of postings. Here he discusses the online handbook of Hungarian chronology.
Although originally published in 1912 (and revised in 1940), Prof. Szentpétery's Chronologia and Calendar of Diplomatics most of the knowledge and tools they provide still prove to be useful for those digging deep into the history of Hungary or that of families. Mind you, these handbooks are written in Hungarian.
It has been online since 2007 at the Hungarian Electronic Library.
The Jewish Calendar section is titled IX. Zsidó naptár és naptári ünnepek and runs from page 35-39.
Yes, it's in Hungarian, but if you are searching your Hungarian ancestors, this might help you with spelling of holidays in that language. I found it interesting.
He addresses other topics of Jewish research interest as well as general resources for everyone, such as maps and databases:
Here: A new book about Hungarian Jewish metrical books - and more Jewish research items. The archivist at the Hungarian Jewish Museum and Archives, Zsuzsanna Toronyi published an article about the history of the archives in the 2007/3 issue of the Levéltári Szemle (Archives Gazetteer, the journal of the Hungarian Archivist Association).
Here: FamilyTrackers.com publishes Romanian Jewish database. A new set of data has been added to FamilyTracker.com's offers. This time their partner in Romania, Marcel Mindrescu added a collection of transcribed Jewish Cemetery records from Oradea, Romania (formerly Nagyvárad, Hungary). The press release also mentions that this is meant to be only the beginning, "the first of many planned from this part of the world".