Set date and time manually in linux shell

# date -s "28 JUN 1984 09:30:00"
# date +%Y%m%d -s "19830628"
# date +%T -s "09:30:00"
# timedatectl set-ntp no
# timedatectl set-time '1983-06-28'
# timedatectl set-time '1983-06-28 09:30:00'