DateDiff

DateDiff returns a number of time intervals between two specified dates

Syntax:

DateDiff (intervalType, startDateTime, endDateTime) 
DateDiff (intervalType, startDateTime, endDateTime, firstDayOfWeek) 

• intervalType is a String expression that is the interval of time you use to calculate the difference between startDateTime and endDateTime.
• startDateTime is the first DateTime value used in calculating the difference. 
• endDateTime is the second DateTime value used in calculating the difference. 
• firstDayOfWeek is an optional constant specifying the first day of the week. 

Returns
A Number value

Whileprintingrecords; 
  Numbervar one; Numbervar two; Numbervar three; Numbervar four; 
  if {Orders.Order Amount} < 1000 then  one else  two;