Thank you for your question on CMS1028, Severe Obstetric Complications. The "day of" operator ignores times and only consider dates when evaluating data. If a patient is admitted at 0600 on 8/5/2023 and a blood transfusion was performed on 8/5 with no time indicated, the "day of" operator will ignore the time and consider the numerator met since 8/5 is during the encounter which started on 8/5. The reason for using the "day of" operator is many hospitals use claims data when mapping procedures. Typically claims data does not contain procedure times. To answer your specific question, Patient A would qualify for the numerator: Delivery encounter start: 8/5/2023 Blood transfusion: 8/6/2023 Delivery encounter end: 8/7/2023 The patient qualifies as the blood transfusion date of 8/6/23 is during the encounter which spans 8/5 to 8/7.