It's easy to track movements in time when the Sun is up (Summer) as it revolves around the horizon. You should be able to tell when it's midday/midnight as the sun will be higher/lower in the sky (the Earth's axis isn't at 90% to the Sun). I guess in the Winter you could use the movement of the stars.
During the winter, the movement of the stars at the horizon can be noted against fixed reference points to give a celestial clock. During the summer, exactly the same principle can be used with the sun, or a pole can be stood in the snow and increments marked around making a 360 dereesun dial