The date and time entered should be the date/time the patient was last known to be well. The time field (1.11) can only be left blank if a best estimate cannot be made (and 'not known' entered for 1.11.2).
For inpatients that had a stroke during sleep, enter the time the patient first woke up after their stroke. If the exact time when the patient woke is unknown, enter a ‘best estimate’.