It's a beautiful day today. Is it a proposition?

Today's fine weather is a proposition, and sentences that can judge whether it is true or not are called propositions. Its essence is a declarative sentence that can judge whether it is true or not. It's a fine day today. It's a declarative sentence, so it's a proposition. Proposition refers to the semantics of judgment sentences, which is a phenomenon that can be defined and observed. Proposition refers not to the judgment sentence itself, but to the semantics expressed.