So I started with Rpi 2 and installed Ubuntu Mate. All worked well during the installation. But then I noticed. The time did not sync. Set at Nov 21 2015 when that particular build was created. I started my search at google and there were few instances reported for time sync issue.
Below is what worked for me
For me ntpdate was not found. So I installed ntp
sudo service ntp reload
Next I tried to update time using following command
date ; sudo service ntp stop ; sudo ntpdate -s time.nist.gov ; sudo service ntp start ; date
Tried to reset timezone
Another issue is to check if the firewall was blocking outbound connection for port 123. Using commands one may get “ntpdate: no server suitable for synchronization found”
sudo ntpdate ntp.ubuntu.com
Modified the config file at /etc/ntp.conf as following
Added few servers
# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
# more information.
Added below line at top
tinker panic 0
And in the end ran command
ntpdate -d servername or ntpdate -u servername
The two ntpdate commands above send, and expect UDP responses, on a random public port number, not port 123, on your computer so they avoid potential complications from using that privileged port inbound. Of course outbound filters could still be a problem.