If date field with time default set to "now" is removed from form, error message about end date

1) Add an date field, default to now, no end date to node form
2) remove/hide that field from the form (whatever panels node/edit variants do when a field isn't included on the form -- setting #access?)
3) submit the form
Get: A 'Start date' date is required if an 'end date' is supplied for field %field. message