we are running version 1.7.5 and even though I thought the issue was solved, we still have a problem with diacritics in the TimeExpressionParser.
The problem occures when we try to save date containing a month with diacritics (which in Czech is a good half of them ) and also when we are searching on those (the search only works for the names of months without diacritics).
I am enclosing our cs_CZ.lang file.
There are several issues preventing this from working, both in character encoding handling and in the cs_CZ locale. I've committed fixes to the develop branch.