This function is used to build calculated value attributes or other expressions that calculate the time between case values that represent dates. For example, suppose we had the following case fragment:

Coupon                   1                       2
SectorFrom              SYD                     SIN
SectorTo                SIN                     LHR
BookingTime       5 Oct 2009 09:00:00     5 Oct 2009 09:00:00
FlightTime        8 Oct 2009 09:00:00    10 Oct 2009 15:45:00

Then we could define a calculated value attribute “HoursFromBookingToFlight” with the formula:

(FlightTime as minutes from epoch using format “dd MMM yyyy HH:mm:ss” – BookingTime as minutes from epoch using format “dd MMM yyyy HH:mm:ss”) / 60

The values of the the calculated value attribute would then be

HoursFromBookingToFlight        72.0    126.73333

Note: The ‘epoch’ referred to is the date 1 millisecond after midnight on the first of January 1970. The raw value of the time between a given date and this date would rarely be of interest.