Sonicwall - How to check logs from previous week?

Last week, we had a bad incident where 3 VPN tunnels from our main site stopped working to remote sites.

Ultimately we reset the PSKs and it was resolved. In the morning, 3 other sites had the same issue and same fix resolved it.

This had to have happened on the sonicwall nsa 2400 at the main site. Upon checking the logs, I cannot find a way to check from certain dates.

The firmware on the sonicwall is 5.9.1.7-2o

Google has not helped.