(let ((new-time (clsql:parse-date-time (remove #\Space value)))
(old-time (when (slot-boundp instance (slot-name slot))
(slot-value instance (slot-name slot)))))
(unless (or (eql old-time new-time)
(when (and new-time old-time)
(equal :equal (clsql:time-compare new-time old-time))))
(let ((new-time (clsql:parse-date-time (remove #\Space value)))
(old-time (when (slot-boundp instance (slot-name slot))
(slot-value instance (slot-name slot)))))
(unless (or (eql old-time new-time)
(when (and new-time old-time)
(equal :equal (clsql:time-compare new-time old-time))))