update your system using alternative ways

update time by script alternative ntp,timedatectl.md

update date and time using http protocol

using curl to update date and time

sudo date -s "$(curl -H'Cache-Control:no-cache' -sI google.com | grep '^Date:' | cut -d' ' -f3-6)Z"

using wget to update date and time of linux/server

sudo date -s "$(wget -qSO- --max-redirect=0 google.com 2>&1 | grep Date: | cut -d' ' -f5-8)Z"

using htpdate

apt install htpdate

usage

htpdate -D -u nobody:nogroup www.linux.org www.freebsd.org

for more https://linux.die.net/man/8/htpdate

using tlsdate

sudo tlsdate -V

More https://github.com/ioerror/tlsdate

another script

https://gist.github.com/jaytaylor/60c8a4e22431c4271200cab68186deb7

More

1. https://askubuntu.com/questions/429306/ntpdate-no-server-suitable-for-synchronization-found
2. https://superuser.com/questions/307158/how-to-use-ntpdate-behind-a-proxy