Thanks for the reply, i got the issue resolved, actually when we use @differenceBetweenDateTimes(Param.StartTime,Param.EndTime,True,"");
when the calendar parameter is blank it takes the Calendar as Default, Default calendar is an instance so i have saved as the default calendar instance, earlier the time was mentioned as 08000 to 170000 that the reason it was giving as 9 hours range i have changed that to whole day as working so now gives result in 24 hours range.
@BusinessCalendar.differenceBetweenDateTimes(.CalculateTime,.CalculateTime," ") function used having the wrong number of parameters passed, Business Calendar has totally 4 parameters to be passed in the above given example the boolean parameter is missed the function used be used as @differenceBetweenDateTimes(.CalculateTime,.CalculateTime,True,"");
One more thing i would like to mention is the boolean value is for using businees calendar or not? so we can pass as it false if it is not needed to calculate based on business days or else we can use true, so remember as it is boolean value we can pass either true/false. for more info on the paramaters please refer the function rule in which detail explanation available in the description.