Consider the table below:
| Name | Date of Birth |
|-------+------------------|
| John | <1978-11-14 Tue> |
| Peter | <1970-11-14 Sat> |
|-------+------------------|
Suppose we want to format time stamps differently, such as with the following elisp commands:
(setq org-time-stamp-custom-formats (quote ("<%d %b %y>" . "<%m/%d/%y %a %H:%M>")))
(org-toggle-time-stamp-overlays)
After realigning the table you get
| Name | Date of Birth |
|-------+------------------|
| John | <14 Nov 1978> |
| Peter | <14 Nov 1970> |
|-------+------------------|
which is wrong because column widths are not uniform. The reason, I suppose, is that when computing column widths, org-mode ignores the fact that the change of time stamps may have altered the length of the printed string.
Best wishes,