Do you use the the some-date field in dynamic table to enter a date value into some-date?
Dynamic Table enters a human readable value into some-date!
See below clip shows how your example work

Or do you fill it manually? or do you fill it by some other widgets?
If so, you need to have your own column template
- simply clone $:/plugins/kookma/shiraz/templates/body/due-date
- fill in
tbl-column-listwith your filed name e.gpublished-on - change the body as you like to format your output (e.g use $view widget)
If still you have problem let me know!