How much time between two clock times
Calculate the elapsed time in hours and minutes between a start and end time of day.
duration = end time − start time, wrapping to the next day if the end time is earlier than the start time
How does this handle an overnight shift, like 10pm to 6am?
If the end time is earlier than the start time, it's assumed to roll over to the next day — so 10pm to 6am is treated as 8 hours, not a negative duration.
Does this work across multiple days?
No — this only measures the gap between two times of day, wrapping at most once to the next day. For multi-day spans, use Date difference instead.