This was a recent bug discovered on the calamares installer which will be fixed in follow up builds. If however you want to try and do it yourself. here is how :
Shift : Boot up in Live mode but dont run the installer yet, first, open the directory /etc/calamares/ as root, open the file settings.conf and find the line “– hwclock” and put a # in front of it so it looks like this ” # – hwclock” . close and save. then run the installer and your problem will be solved.
Lindoz : Same as above except the settings file is in /usr/share/calamares/