I run a GPS-based Raspberry Pi as an NTP server and have set up my Omega2 devices to get the time from that. So far so good. However, I'm trying to find an NTP client using opkg and can't find one.. What do I need to use?

Thanks in advance.

The command line utility is named ntpd (technically it is part of busybox, like most command line tools are in openwrt).

Ususally, you don't need to manually call it, as it is set up to run at system start automatically. It synchronizes the time from the openwrt/lede pool of ntp servers by default. You can see these using openwrt's UCI configuration tool:

# show system's ntp settings
uci show system.ntp

You'll get something like:

system.ntp=timeserver
system.ntp.server='0.openwrt.pool.ntp.org' '1.openwrt.pool.ntp.org' '2.openwrt.pool.ntp.org' '3.openwrt.pool.ntp.org'
system.ntp.enabled='1'
system.ntp.enable_server='0'

If you want to change the ntp servers, you can do that using UCI as well:

# delete existing list of servers
uci set system.ntp.server=
# add one or more servers
uci add_list system.ntp.server='my-ntp-server.org'
uci add_list system.ntp.server='my-other-ntp-server.org'
# commit the changes
uci commit
# have (sys)ntpd reload its own config
/etc/init.d/sysntpd reload

uci set system.@system[0].timezone='UTC'
uci commit system
reload_config

If you're outside the US as I am the timezone is a little more complex:

uci set system.@system[0].timezone='AEST-10AEDT,M10.1.0,M4.1.0/3'
uci set system.@system[0].zonename='Canberra, Melbourne, Sydney'

there is a ntpd installed and running already as client

Ah, I see! That makes sense now. So all I really need to do is to write the time to the OLED at regular intervals - every minute is good enough - and ntpd will take care of fetching the time.

Great! Thanks ...