The -T option lets dmesg show user readable time.

Example:

$ dmesg -t
...
[Sat Nov 15 12:15:12 2019] CPU1: Package temperature/speed normal
[Sat Nov 15 12:14:12 2019] CPU3: Package temperature/speed normal
[Sat Nov 15 12:14:12 2019] CPU0: Package temperature/speed normal
[Sat Nov 15 12:14:12 2019] CPU4: Package temperature/speed normal
$

dmesg time options

$ dmesg -h | grep time
  -d, --show-delta            show time delta between printed messages
  -e, --reltime               show local time and time delta in readable format
  -T, --ctime                 show human-readable timestamp (may be inaccurate!)
  -t, --notime                don't show any timestamp with messages
      --time-format   show timestamp using the given format:
                                [delta|reltime|ctime|notime|iso]
Suspending/resume will make ctime and iso timestamps inaccurate.