memotech

Sorry, we misunderstood,
The function of calculating the difference between the 2 dates works very well.

Now I would like to sum two time differences. See photos and explanations above. I used :

DATETIMESUM(fieldname1,'h:i',TIMETODECIMAL(fieldname13,'h:i','i'), 'i')

But it does not work.
the fieldname1 and fieldname13 are the results of the formula you sent me

fieldname1 :

(function(){var o = DATEDIFF( fieldname4, fieldname3, 'hh:ii', 'h');
return CONCATENATE(o['hours'], ':', o['minutes']);
})()

fieldname3 :

(function(){
var o = DATEDIFF( fieldname12, fieldname11, 'hh:ii', 'h');
return CONCATENATE(o['hours'], ':', o['minutes']);
})()

fieldname15 :

DATETIMESUM(fieldname1,'h:i',TIMETODECIMAL(fieldname13,'h:i','i'), 'i')

is that more understandable?

thanks

ok thanks a lot