Late to the party, sorry; but I currently do all my historical information in Excel files (LibreOffice Calc, actually, but same dealio).
I have each of my major countries listed across the top and a timeline from the more-or-less beginning of recorded history downward, and have frozen the panes so I can easily scroll to a particular country heading and enter relevant dates or eras. I also have conditional formatting turned on so that if I enter anything in an area, it highlights in a particular color for easy viewing.
Right now, that's been the best way for me to get around it until RW supports calendars and exporting. I should also point out I don't use RW as an at-the-table tool, but rather as a comprehensive database for my world, so this spreadsheet is a sort of in-addition-to tool.