Without installing any more packages...
Turn NTP off, manually set the time to be close enough, turn NTP back on:
Set NTP Service inactive
$ timedatectl set-ntp false
Set the time manually
Yeah, that's sad but it works and you don't need to muck around installing anything and make it work. Get the approximate LOCAL time from the wall clock, your phone, the Internet. It doesn't need to be perfect because we'll turn ntp back on in a moment...
$ sudo timedatectl set-time "2019-06-22 13:41:00"
Set NTP service active
$ sudo timedatectl set-ntp true
Local time: Sat 2019-06-22 13:49:53 AEST
Universal time: Sat 2019-06-22 03:49:53 UTC
RTC time: Sat 2019-06-22 03:49:54
Time zone: Australia/Sydney (AEST, +1000)
System clock synchronized: no
NTP service: active
RTC in local TZ: no
The "System clock synchronized: no" will turn to "yes" when it has adjusted enough to be considered 'in sync'.
$ cat /etc/systemd/timesyncd.conf
$ timedatectl timesync-status
Server: 220.127.116.11 (au.pool.ntp.org)
Poll interval: 8min 32s (min: 32s; max 34min 8s)
Packet count: 0
$ grep systemd-timesyncd /var/log/syslog | tail
Jun 22 14:13:09 meebox systemd-timesyncd: Timed out waiting for reply from 18.104.22.168:123 (au.pool.ntp.org).
My ntp packets were being blocked by the corporate firewall.