I did try this:
"Its defined in /language/en-GB/en-GB.tpl_ja_alpha.ini
TPL_CLIENT = "Client"
TPL_DAY = "Date"
TPL_TYPE = "Type"
TPL_CATEGORY = "Category"
TPL_LINK = "Link"
TPL_RATE = "Rating"
However there was no change to the title names, even after changing "Client" to "Event".