It should straighten out after few gracefull shutdowns, as it seems to me
ref: Debian - two entries in `last reboot` in `still running` - Unix & Linux Stack Exchange
ref: What is the purpose of the 10th column of the `last` command's output? - Unix & Linux Stack Exchange
ref: linux - Interpreting last reboot output - Super User
ref: https://www.cyberciti.biz/tips/linux-last-reboot-time-and-date-find-out.html
Moreover, you may also use
uptime
last reboot -F
sudo su
hwclock -r
etc
However, I can see that the date is returned in a correct way. Also I pressume that ntp is enabled as per default.