[EpiData-list] Re calculation formula

Hello! I need to calculate the sum of hours and days, in form of hours. So I did the formula as : total hours = days*24 + hours So when you have one day of time to be registered, and you have no umber of hours (i.e. zero), it is writting as "00" (two digits of zeros), then the "total hours" would give answer as "0", even though the number 1 is writting in days. When I triy to write the zero, as one digit (i.e. "0"), then it works fine. Any tip how to overcome it?

Here is below a copy of the formula: d8 MUSTENTER AFTER ENTRY LET d10=d9*24 + d8 END END

Thank you in advance! /Ziad