For how long can I cache cursor value to next query


I am developing an application to fetch followers and friends ,so When I want to retrieve the user friends ids, I need to loop 15 times through the cursored 5000 results. but if the user has more than 15*5000 = 75000, I should delay the script until the next time interval 15 minutes. that is the classical strategy I am using for now . What if I want to store or cache the next_cursor value to the next visit which may happen after an hour, a day or a longer period of time . Or in other words, what if I want to start fetching results starting from page (cursor value) =15 , does twitter will respond by the page 15 or I have to start from the beginning again .
Thank you