Setting the time in Arch using NTP

First, check what is currently managing time:

timedatectl status

Look for:

System clock synchronized: yesNTP service: active

If either of those says "no", that's likely the issue.

Using systemd-timesyncd

Arch can use systemd's built-in NTP client:

sudo systemctl enable --now systemd-timesyncd

Then:

timedatectl set-ntp true

Check status:

timedatectl status

And:

timedatectl timesync-status

You should see which NTP server you're synced to and the estimated offset.