"寒假什么时候开始？"

Translation: When do the winter holidays start?

[Julestheman]

When do the winter holidays start*

[emperorchiao]

Or "when does winter break start"

[sarefo]

Always report things like that, too. The contribs might not see it here.

[pkoutsenko]

Break, vacations are just as correct

[PeaceJoyPancakes]

Not "vacations", but "vacation". And then you need "when does".

[NaturalStream]

I wrote: "When will winter vacation start?"

[ArtBurnap]

I tried about three or four grammatical alternatives, but none was accepted. Reported each one.

[deactivated user]

Yet...

[lijenazmija]

"Begin" should also be accepted.

[zoukp]

When does the winter vacation start?

why isn't this sentence a correct translation? :o

[PeaceJoyPancakes]

It's fine. Report it.

[the_Jett]

Most natural translation should be, "When does Winter break begin/start?" or "When does the Winter break begin/start" or just, "When is Winter break?".

[Chris213738]

When will ...

[Burento]

Do people not say 冬假 or 冬天假?

[PeaceJoyPancakes]

"冬假" is non-standard. It does seem to occur, but at a rate of maybe one or two percent as commonly as "寒假", and would probably seem weird to most native Mandarin speakers. It doesn't show up at all on Google's Ngram Viewer, but it shows up in a Google search.