I use multiple Raspberry Pi devices for mining and I see this type of error a lot. It almost always comes down to the SD card and/or the power supply. If it happens once a day around the same time, I would bet it is the SD card. The device is probably trying to run some cron job and the file systems takes a dive due to SD card issues causing a kernel panic.
Thanks for the response. So far the crashes stopped since adding the config change recommended by vh few posts back. Could be coincidence we'll see but it was crashing at least daily before. I'll keep this in mind though.