GET New Orders Between From Date and To Date

we have one question..We need to pass PageNumber while Get New Orders API IF I have not pass so It takes default 1 page..so my question is how we know that how many pages are there..for ex there are 200 new orders...so we need to get order 1 to 20 pages each page 10 orders..

so how we know that total number of orders or we need to call api until 20 pages..
Is there any possiblity to get order between from and to date.