Reference material available here:

HyperCard scripts to search and replace text   autoReplace.html  
list of 256 kanji in traditional and simplified forms; explanation kyukanji
kyukanji_notes
Meiji, Taisho, Showa and Heisei calendar conversion mtsh
Japanese era names from 650 onwards
in standard Japanese encoding or Unicode 
nengo
nengo-utf8
chronological list of classical Japanese works
(just a fragment, for more lists of title see
pmjs site trans. index)
sakuhin

tools/reference available elsewhere

Internet Resources for Asian Studies: very useful report by Cathy Chiu on AsianDoc. 

For Chinese dates see  Chinese and Gregorian calendar