The timezone is set via timedatectl, for example to switch to London time:
timedatectl set-timezone Europe/London
You can list available timezones via timedatectl list-timezones. System time can be set via set-time:
timedatectl set-time 1990-11-30T17:30:00Z
I use chrony as an NTP daemon, which is run using a systemd service (installed with the package). See Systemd for more info.