Hey Phil, As noted above it's like "probably", and the person replying isn't fully convinced by their own answer. When do you usually get up? 9? 10ish? I would say it sounds something like the above. 你的中文一點也不糟糕！要有信心！:) Laurence

“吧”在这里表示大概的，不是很准确的。像回答中的“九点多吧”表示大概九点多，如果省略“吧”，则就表示“九点多”。一个确切的数字可能会更明显，像: A: “你语文考了多少分？” B: “九十二吧，大概，我也记不清了” (“大概，我也记不清了”可省略。) “九十二吧”表示大概是九十二，可能是九十二。如果回答“九十二”则表示就是九十二。 你的中文一点也不糟糕😂 相反，很好。

You can omit it, but omitting it will give the speaker an aloof tone.

吧 表示不太肯定的语气词，是否真的是九点多不确定。但可以省略，省略之后语气就变得更加肯定了，表示确定是九点多/九点过后9~10点之间/。

If someone asks me this question, I won't reply like this. “九點多吧” just doesn't sound natural to me for responding to this question. But if someone asks me “明天你想要我幾點找你？”，it is fine to reply with “九點多吧”。However, this is not an enthusiastic response （這是不是一個熱情的回复）。If you say this to a girl whom asks you on a date, in this phrase "吧” will make her feel you are not very serious with this date.