General

While you can sync time within indi-allsky, it is much better to just let ntpd handle time sync itself with a GPS module.

Install gpsd

Ensure your GPS adapter is plugged in.

./misc/setup_gpsd.sh

Install ntpsec

sudo apt-get install ntpsec

Configure

Add the following to /etc/ntpsec/ntp.conf

# The magic pseudo-IP address 127.127.28.0 identifies unit 0 of the ntpd shared-memory driver (NTP0)
server 127.127.28.0 minpoll 4 maxpoll 4 prefer
fudge 127.127.28.0 refid GPS stratum 1

# Uncomment if not connected to internet
#tos minclock 1 minsane 1

Validation

Use ntpq -p to validate time is syncing from GPS.