A pin saving way to display many sensor information

Hello, I have a project where i want to make a clock where everything you see and touch with feel analogue but everything behind the scenes will be digital (more or less)

the reason i want to do this is so as if by magic this grandfather clock looking thing is displaying weather forecasts on revolving discs threw viewing windows and all sorts of humidity, temperature, time of sunset, sunrise ... you get the picture.

also i would like to have a 2 dimensional map of the solar system viewed from above ran of a stepping motor and some laser cut gears.

i am planing to buy a wifi module and borrow weather data from a website and calibrate the clock whilst I'm at it.

i found that the 16MHz oscillater in the arduino is not stable enough so am investigating how to implement a standard quartz clock with a tracking wheel attached to the second hand. or receive the signal from a quartz crystal and control the clock with a steppe motor. any extra ideas would be appreciated?

my biggest question at this stage is how would you move the multiple needles that are displaying the information?

Stepper motors seem the most accurate but require a lot of pins. so i was thinking about using 5V voltmeters or servo motors with a 2:1 gear ratio in combination with a 74HC595 or 2.

Could a matrix be implemented?

Thanks

You need to use an external clock , such as DS3231 which is accurate.

Stepper motors are the way to go, model type servos do not rotate 360 degrees.

I'd suggest you get a basic clock working first, then worry about all the other stuff, as it sounds a huge mechanical exercise if nothing else.

Stepper motors seem the most accurate but require a lot of pins. so i was thinking about using 5V voltmeters or servo motors with a 2:1 gear ratio in combination with a 74HC595 or 2.

There are a lot of modern stepper motor drivers that need only 2 pins (each). One for step and and one direction. Steppers do not know where they are at startup. You need some way to "home" them.

Stepper basics.