SkyWest Pre-Entrance Practice Exam

A calendar day is the 24-hour span that runs from midnight to the next midnight in local time, so 0001 local time through 2400 local time constitutes one calendar day. This way of defining time is used for daily records, logs, and duties tied to the date on the local clock. The other terms are unrelated to the concept of a day: ATC refers to Air Traffic Control, a connection isn’t a time-period term, and a bulkhead is a structural partition. So the 0001–2400 local period is the calendar day.