For example, if you run a report every month, previously you need to change the date criteria in each month you running the report (ie. “01/06/2010..30/06/2010”, “01/07/2010..31/07/2010”, etc).
Now you only need to enter (monthRange(0, 0)) which will automatic return the correct first day and last day of the month.
Refer to the SysQueryRangeUtil class – there are other useful methods such as dateRange(), currentEmployeeId(), etc. It’s also possible to create new method on this class for special purpose!