[time-nuts] Clock display on Linux systems?

[Adam Space]

Most distributions of Linux already have a "clock" application that shows
the system time, but I am wondering how to program a more customizable
display on a Linux system / Raspberry pi. There are a few solutions that
pop up by googling the issue, but these are all insufficient. For example,
the only solutions in Python (which I would prefer to use if possible, but
not necessary) I have found are 1) using a library like pygame or tkinter
to build a display or 2) doing something more barebones like displaying the
time and sleep() ing for a second. 1) is terribly inefficient for a display
of accurate time, because either you have a refresh rate that is low and
the clock updates with significant lag, or you have a high refresh rate
which eats up large processing power. 2) is also inefficient because the
frequency of a local clock may be poor, so long term accuracy can only be
sustained with synchronization via NTP for example.

Perhaps there are lower level Linux commands that could be used for this?
I'm not sure. Any suggestions are welcome.

Adam