Timestamp attribute with an invalid time in it is read only - editor ignores entry

After putting bogus data into a timestamp field (SYNTAX 1.3.6.1.4.1.1466.115.121.1.24) using ldapmodify, a search of that entry displays correctly in the entry editor, but is not editable.

The "edit value F7" option is available, but does nothing when selected.

Ideally the option should be made to edit the entry, along with the warning that the previous time value was corrupt and a new one should be chosen.