What does 九時半まで mean here?

[Jaffa]

Hello,

I came across this sentence and I'm not sure what it means.

Sentence: 日曜日は 九時半まで ねました。

Does it mean "On Sunday I slept until 9:30" and not "On Sunday I didn't sleep until 9:30?"

Thank you.

 

[undrentide]

九時半まで means until nine thirty.
Your first interpretation is correct.

 

[Toritoribe]

The negative sentence 九時半まで寝ませんでした can mean both "I hadn't go to bed before 9:30 and fell asleep at 9:30." and "I had fallen asleep and woke up before 9:30", thus, it exactly means "I didn't sleep until 9:30" including its ambiguity.

 

[Jaffa]

The negative sentence 九時半まで寝ませんでした can mean both "I hadn't go to bed before 9:30 and fell asleep at 9:30." and "I had fallen asleep and woke up before 9:30", thus, it exactly means "I didn't sleep until 9:30" including its ambiguity.

I don't quite understand how the two meanings (particularly, "I had fallen asleep and woke up before 9:30") make 九時半まで 寝ませんでした exactly mean "I didn't sleep until 9:30".

But looking at the answers, this is what I understood:
I slept until 9:30 = 九時半まで 寝ました
I didn't sleep until 9:30 = 九時半まで 寝ませんでした

 

[Bouxcuengh]

確かに曖昧な日本語ですよね！