When do cats give birth to kittens?

Cat's expected due date: Cat pregnancies usually last around 65 days, and preparations for birth should begin about two months into the pregnancy. It is best to place the cat in a quiet room, prepare a soft cat bed, some pee pads, umbilical cord ties, scissors, and gloves for cutting the umbilical cord.
If a cat starts to give birth after only 50 days or so, it may be experiencing a premature birth or the owner may have misjudged the pregnancy timeline. Premature births often result in stillbirths and may not lead to live kittens.

Signs of labor in a queen cat:

Before labor, the queen's abdomen will become noticeably swollen and saggy, her breasts and nipples will enlarge, and her nipples may protrude and turn a deeper pink. Sometimes, colostrum may leak out. As labor approaches, a sticky fluid may leak from the queen's vulva, her uterus will begin to contract, and she will appear uncomfortable, accompanied by signs of pain. The queen will become more nervous, which means she is about to give birth.

Signs that a queen cat is about to give birth:

The queen's abdomen enlarges, her breasts fill with milk, and a cool milk flow can be obtained by gently pinching her nipples. The queen becomes restless, repeatedly standing up and lying down, with accelerated breathing. She will occasionally urinate transparent urine, and labor contractions will begin before giving birth. The queen will emit a howl due to the pain caused by uterine contractions during labor.

How to handle a queen cat giving birth:

Try to maintain a quiet environment around the queen during labor to facilitate a smooth delivery.
Prepare a nest for the kittens as early as possible, ensuring that the bedding is warm, comfortable, and clean.
Monitor the queen's movements constantly. If she has no experience in breaking the amniotic sac, help her in time to prevent the kittens from suffocating.