Add ability to show a duration such as "27:15" for 27 hours 15 minutes?

Examples of different formats:

27:15
27 hours 15 minutes
1 day 3:15

Currently you have to use a date field which only works for values that represent points in time (so durations beyond 23:59 are not supported) or a decimal field representing, for example, 27.25 hours.

This could either be an option for date fields, allowing currently 'illegal' date/time elements such as 400 days or 27 hours.

Or as a "show as duration in [days/hours/minutes...]" option for decimal fields, allowing a fractional value such as 27.25 to be formatted as a time.