This probably is an issue with a broken rtc or isa from your BIOS, to test this, disable the hwclock call in calamares. To do this, in live mode open this file:
kate /usr/lib/calamares/modules/hardwr/main.py
Then comment out line 36 - 43, see https://github.com/KaOSx/calamares/blob/master/src/modules/hardwr/main.py#L36
So after editing those lines look like:
#root_mount_point = libcalamares.globalstorage.value("rootMountPoint")
# try:
# subprocess.check_call(["hwclock", "--systohc", "--utc"])
# except subprocess.CalledProcessError as e:
# return "Cannot set hardware clock.",\
# "hwclock terminated with exit code {}.".format(e.returncode)
# shutil.copy2("/etc/adjtime", "%s/etc/" % root_mount_point)
and save, it will ask for a password then, it is root
. After that start Calamares as usual.