Exporting the gradebook's grades into a spreedsheet (formats: XLS, ODS, CSV) results with a last column (['timeexported'] = 'Last downloaded from this course') displaying raw php time() function output, which is "number of seconds since the Unix Epoch (January 1 1970 00:00:00 GMT)." and which is unclear for teachers and confusing.

Could not find the original intent for adding this info the the sheet's last column on the tracker and the Moodle documentations.

Suggests:

1. Display a more meaningful (human readable) time format.
2. Or...Discard the column.

Can be experienced when downloading the users grades from:
https://qa.moodle.net/grade/export/xls/index.php?id=2