Hours interval

Looking for a formula that will calculate the number of hours when the start time and end time span more than 24 hours

You may use TEXT(, “[HH]”) to get the string with requested value.
If you need a number, you may multiply your datetime value by 24, and have a float with whole part as number of hours, and fractional part as fraction of an hour (rationale: datetime is a floating-point value that represents time as number of days). Formatting the result as Number (opposed to Time) will give you result in convenient form.

Thanks. I will try that