can someone explain to me what it means?

[Lily of the valley]

I don't understand what 'a day's notice' means in this context: "I can also work overtime with a day’s notice. "

[emsr2d2]

I don't understand what 'a day's notice' means in this context: "I can also work overtime with a day’s notice. "

It means that the person is happy to work overtime as long as they are asked to do so one day before they are required to work.

If the boss wants her to work extra hours on Tuesday, he will need to ask her on Monday at the latest.

[Lily of the valley]

Now I understand it. I thought it had something to do with money.

[riquecohen]

Now I understand it. I thought it had something to do with money.

Emsr2d2 has answered your question. I'd like to add that although money is not mentioned in your original sentence, there could be some financial considerations involved. In the US, the Fair Labor Standards Act provides that overtime in excess of 40 hours a week be paid at a rate of one and a half times the regular pay rate