Convert value from timestamp into int and increase value

[#1]

Goal:

Display value in hours as integer after completed calculation that is (answer = end - begin),

Problem:

After doing calculation you gain the result based on the sourcecode below. Some example of result is:

02:54

04:35

65:25

25:15

I need to make the value to become:

Current data       Requested result

-----------------------------------------------------

02:54            >   03 or 3

04:35            >   05 or 5

65:29            >   65

25:15            >   25

123:32          >   124

The main problem is

I don't know how to do it based on the source code below.

If the number is higher than 29 the result will be increase with one value   (12:30 wil be 13)

Begin	End
2011-11-10 12:12:12	2011-11-12 12:12:12
2011-11-10 12:12:12	2011-11-11 08:12:12

(The column Begin and End have timestamp as number format settings in doucment settings)

The source code is

INTERVAL

(

     End - Begin

     , 'hh:mm'

)

or

INTERVAL

(

     End - Begin

     , 'mm'

)

// JJ