Exported data has no time stamp, only year and day for all data points. i.e. 2011-12-24 0:00 Also, had to rename the xls to xlsx to open in Oo. Just passing time waiting for Santa.
I think it has to do with the way Excel formats the date. You can probably right click on that column and change the format string something else.
Formatted both date and time to YYYY-M-D H:MM but still got the same results.