A camera recorded one frame every minute (day and night) for two separate three-week periods in autumn and spring. The film is shown on two adjacent screens, each having a soundtrack that was recorded on a sampling basis. The left hand screen was shot at the autumn equinox and the right-hand screen at the spring equinox. The structure of the film is based on the rotation and tilting of the earth as we pass from summer to winter and back. The centre of the film coincides with the equinox and is the point at which day and night are the same length on both the left and the right screen.