"I wake up in the evening."

Translation: मैं शाम को जागती हूँ।

[WannabeSmile]

Why is the postposition here 'ko' when in other things related to time it is में ? For example वह दोपहर में घर आता है (and not दोपहर को).

[GraysonElliott]

"Ko" doesn't seem as unintuitive of you consider usage of "tonight" in English, i.e. "Let's meet at 10 tonight." Not exactly the same usage as "at", but makes Hindi grammar less frustrating for me here. =)

[StormMaashrooms]

its not मैं संध्या में उठता हूँ?

[RanzoG]

"ko" is used when stating the time of something, rather than translating the English "in." Literally, it's like "at the evening."
As for shaam, it sounds to me like the normal word. Jaagna is wake up, verses uThna = get up.

[Sam362597]

Is the postposition necessary or can it be skipped? I was marked wrong for leaving it out, though there was no postposition in a previous example (something like 'We wake up in the morning').

[Nina427848]

It is necessary in this sentence, in the context of शाम. In the context of सुबह the को is often skipped.

[StormMaashrooms]

Thanks again

[emrys29]

Just so you know, your proposed sentence is not wrong. The sentence in the answer is comparatively better. Your sentence looks correct to me as a native Hindi speaker and everyone will understand what you mean to say.

[Prachi541265]

शाम and संध्या are same but शाम is used commonly nowadays.

[arebhai]

What are approximately the times of the day for sham ko and rat ko?

[Zerenei]

Same as the times for evening and night! I would say evening is around 5-10pm and night is after that. There's not really an exact answer.