Zahari Zograf's fresco 'The circle of life' (ca 1850), Transfiguration Monastery, near Veliko Tarnovo in Bulgaria.

Zahari Zograf's fresco 'The circle of life' (ca 1850), Transfiguration Monastery, near Veliko Tarnovo in Bulgaria.
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The 'Day and Night' cycle is represented by two angelic characters who are managing a rope which runs through the wheel. The Day is on the left, and the Night is on the right.

At the outer ring of the circle, we can see the key stages in life. Each of them is marked with a number which stands for a certain age: 4 - toddler, 14 - teenager, 21 Young adult, 30 - The heights of youth, 48 - man, 56 - The beginning of the old age, 70 - elderly, and the scythe of Death awaits at the end.

The middle ring contains the four seasons and the last one indicates the twelve months.

Right at centre of 'The circle of life' stands the Whore of Babylon. As described in the Bible:

"17:4And the woman was arrayed in purple and scarlet colour, and decked with gold and precious stones and pearls, having a golden cup in her hand full of abominations and filthiness of her fornication."

In other words, a metaphor for a "momentary and lustful life".
~This is Christian Bulgaria