SPOILERS - About the ending

I assume it was deliberately left ambiguous. We don't know if he went to work or not.

Talking of spoilers, the lingering shot of the notebook on the sofa signalled exactly what was going to happen next.

I agree with the fact that he begins to consider himself a poet at the end of the film but I don't think he will quit his job.

During his conversation with the japanese man, he realises that other poets had regular jobs too. For example, William Carlos Williams never stopped being a doctor while writing as far as I know.

Beside, I think his daily life, his routine, is where he takes his inspiration from. Driving allows him to clear his mind and let the words flow. It's a kind of repetitive beat on which he can improvise, just like the rapper in the laundromat.

That said, it intrigued me that we couldn't see the time on his watch at the end so you might have a point. The light outside seemed the same though.

Paterson's poetry was never about commercial success. It was for himself. He wasn't writing it for practice, or anything like that, it was merely a hobby. This is reinforced by the other poets he meets in the story: he came across Method Man (err, "some guy") rapping in an empty laundromat, but Method wasn't about sharing it. "I'm still working on it." His poetry was his own. The girl he met kept her poems behind lock and key, in her "secret notebook." And the Japanese man, on a poetry pilgrimage to America, he had *multiple* notebooks full of poetry, yet was clearly still not professional. Just a personal pursuit. Paterson was the same.