need to get a list of cs-client-addr for a period of time hitting a VIP

F5 doesn't track historical vip session record. If you are sending all logs to remote management server, then configure high speed login(HSL) profile in each VIP and LB will capture client details(i.e Source IP, Port, etc) & forward to log server. Where you can customize data based on requirement.

https://devcentral.f5.com/questions/logging-the-request-coming-to-a-virtual-server