Question

Is there a way to represent a time value in Excel where hours can be 24 and above?

For example, have a time that would be 25:00:00 for 1 AM on the following day (common representation in mass transit scheduling).

It can’t just be plain text, because I want to be able to perform calculations on them (averages, standard deviation for example) or chart them.

Answer 1

It’s already the case that if you put a date or a time into a cell, you get a datetime value.

For example, type 14:00 into A1 and A2, and set A3 to =A1+A2. Why does it display 04:00, you might wonder. The answer comes if you set the cell format to something that displays date and time, eg dd/mm/yyyy hh:mm. Do this to A1 and A2 as well and we see:

• entered pure time values are stored as a datetime with the entered time portion, and a date portion of January 0, 1900
• doing math on datetimes is possible and becomes comprehensible once you know that zero corresponds to midnight on January 0, 1900, and that one unit = 1 day

So to do what you want – to store 25 hours in a cell and have it understood by both users and Excel to mean 25 hours – just put a value of 25/24, and a custom format including the magic format code [h], the [] here meaning ‘allow the displayed value to go over 24’.