My interpretation: The central figure is the Sun God and he holds the two halves of the year. In his right hand the 1st half year ends with a half-circle at midsummer. It is formed like the high dome of the midsummer sky.

His left hand holds the 2nd half of the year, depicted with a kind of Y (the necks and heads of two small birds). His hands are located at the equinoxes.

The year begins in midwinter (bottom left from us seen) and moves upwards to midsummer (top left). Then via a jump to the right (from us seen) the Y sign arrives. It is located at the beginning of the 2nd half of the year.

Below the equinoxes (at his 4-fingered hands) the 'staffs' are black. Only from spring equinox to midsummer it there truly a lifegiving light.

The heads of the two great 'bird staffs' (seasons) are hanging down and their 'tails' are at midsummer. The central line divides the year into two similar, yet clearly different, halves. In the vertical middle of the central line is a curious creature with a three-fingered tail at right (from us seen). The 'tail side' of the year is the 'back side' of the year, the left side.