mono/mono — pull request #1151 by danielrh (2014-07-09 07:09:38+00:00)
Title: Fix https://github.com/OfficeDev/Open-XML-SDK/issues/6 making date W3DTF

core.xml's date elements need to be in precisely the right format for other tools to read them properly.
Specifically other consumers of
https://github.com/OfficeDev/Open-XML-SDK/issues/6