The baby is just one day old and has not yet left hospital.

那个婴儿才出生一天，还没有离开医院。

youdao

THE baby is just one day old and has not yet left hospital. She is quiet but alert.

一个刚刚来到人世仅一天的婴儿，尚处于医院监护中，安静却警觉。

youdao

I wear my old shoes every day. One sole has come unglued.

我天天穿我的旧鞋，一个鞋掌掉下来了。

《柯林斯英汉双解大词典》

John Henry started growing when he was one day old.

VOA: special.2009.02.21

One day, while Giovani was looking out his window, he saw an old man in a black cape walking in the garden.

VOA: special.2009.05.23

Then one day, Everett saw that his chair in the living room was getting old.

VOA: special.2009.03.07

It is always less than one day old, never older then the evening milking the night before the morning on which the cheese is made.

FORBES: The King Of Cheeses: Why Does It Taste So Good?

To compare this to fish, one would have to extract the mercury out of the fish tissue and inject it into a one day old baby.

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He is bullied and beaten until one day an old man gives him a bag of crocodile tongues.

BBC: Roald Dahl and the darkness within