February 21 was the Day of Ishtar, and Day of Nut, to some ancients

Day of Ishtar, Babylonia

Goddess of Love and Battle from the region of Mesopotamia (Greek for 'between the rivers', ie, between the Tigris and Euphrates rivers), the area now known as Iraq, and from Assyria. Ishtar is the counterpart of the Phoenician Astarte.

Her name is said the be associated with the word 'Easter', because of her associations, like Easter, with springtime and fertility. The meaning of the name is not known, though it is possible that the underlying stem is the same as that of Assur, which would thus make her the 'leading one' or 'chief'. She was known as Inanna in Sumerian mythology. She is a life-death-rebirth deity, daughter of Anu, the god of the air, mother and consort of the farm god Tammuz, who is similar to the Greek Adonis. She was usually described as an evil, heartless, women who destroyed her mates and lovers. 

"In the astral-theological system, Ishtar becomes the planet Venus, and the double aspect of the goddess is made to correspond to the strikingly different phases of Venus in the summer and winter seasons. On monuments and seal-cylinders she appears frequently with bow and arrow, though also simply clad in long robes with a crown on her head and an eight-rayed star as her symbol. Statuettes have been found in large numbers representing her as naked with her arms folded across her breast or holding a child. The art thus reflects the popular conceptions formed of the goddess. Together with Sin, the moon-god, and Shamash, the sun-god, she is the third figure in a triad personifying the three great forces of nature - moon, sun and earth, as the life-force. The doctrine involved illustrates the tendency of the Babylonian priests to centralize the manifestations of divine power in the universe, just as the triad Anu, Bel and Ea - the heavens, the earth and the watery deep - form another illustration of this same tendency."   Source

"... in the great epic of Gilgamesh, she tried to make Gilgamesh her husband, but he refused her and reminded her of her former lovers, whom she mercilessly killed or left injured. She reported this to her father, Anu, and he gave her the mystical bull of heaven to avenge herself. Gilgamesh and his friend Enkidu stopped and killed the mighty creature and threw its headless body at her feet. They also insulted her, and she responded by sending disease to kill Gilgamesh's best friend Enkidu. She is one of Aphrodite's counterparts."   Source: Encyclopedia Mythica

Deities of many cultures in the Book of Days

Nut and Geb, courtesy Ancient Egypt - KingTutOne.com a Resource Centre for Ancient Egypt

Day of the goddess Nut, ancient Egypt

In Egyptian mythology, Nut (Nuit), daughter of Shu and Tefnut, was the goddess of the heavens and sky. It was believed that the world was created by a divine act of sex between the earth god Geb and the sky goddess, Nut; the goddess Nut was on top, while Geb reclined.

The sun god Re entered her mouth after the sun set in the evening and was reborn from her vulva the next morning. She also swallowed and rebirthed the stars.

She was a goddess of death, and her image is on the inside of most sarcophagi. The pharaoh entered her body after death and was later resurrected.
In art, Nuit is depicted as a woman wearing no clothes, covered with stars and supported by Shu; opposite her (the upper area, the sky), is her husband, Seb, the Earth. With Seb, she was the mother of Osiris, Horus, Isis, Seth, and Nephthys ...