Reports/logs download in Excel format shows wrong time.

I have identified a problem when I run a log report on student activity in in Moodle: the date/time in the "Display on Page" is different to what I "Download in Excel format".

I discovered this when a lecturer asked to me find out when a student uploaded his assignment files. The "On page" showed he uploaded on Tuesday 13 May at 12:43am and 12:45am. The Downloaded excel file showed he submitted on 12 May at 14:43 and 14:45. (see attached excel file and screen shot). So I tried running another log for the same student on 19 May, and am getting the same pattern happening - the excel report I download shows minus 10 hours difference to what is displayed on the screen.

I have opened the Excel download file in both Excel and OpenOffice, with the same result. The other display formats all do not have this problem (page, text and ODS).

Does the fact that this behaviour can be reproduced in Excel and OO imply that the issue may be in the XLS file itself?