A solar day is the time it takes for the Earth to orbit around the Sun.

I couldn't understand the state of his behavior.

That great demon had the power to destroy the village.

I strive for body care by doing moderate exercise and eating a balanced diet every day.

She was a secret kunoichi (female ninja).

"Once in a lifetime" means to cherish the encounter that happens only once in one's lifetime.

He missed a once-in-a-lifetime opportunity.

He was focused on his work all day long.

No one knows what he did to spend one day.

This day was a very rare day for me.