今日はもう

not any more today; that’s it for today, For today, ... now

→ 今日
phrase Rare #30,459
not any more today; that’s it for today Sets a limit for today: something will not happen or be needed again today.
JA: 今日はもう何もすることがないんだ。
EN: I have nothing else to do today.

私は今日はもう用がない。

I don't have anything else to do today.

今日はもう聞かないよ。

I won’t ask anymore today.

今日という今日はもう許さんぞ!

Today, of all days, I’m not letting you off!

— ロード・オブ・ザ・リング (2001)

今日はもう何もすることがないんだ。

I don't have anything else to do today.

今日はもう誰も来ないと思う。

I don't think anyone else is coming today.

phrase Rare #37,846
For today, ... now Used to say that, at this point in the day, it is time to do something or stop for the day.
JA: 今日はもう寝よう。
EN: Let’s call it a day and go to bed.

今日はもう帰っていいよ

You can go home now.

— Departures (2008)

今日はもう寝よう。

Let's go to bed for today.

今日はもう寝ろ

Go to bed already.

— レオン (1994)

今日はもう帰りたい。

I just want to go home now.

今日はもう寝る?

Are you going to bed already?