"Demi waktu."

Translation: For the sake of time.

[Serfive]

Why not 'for time's sake'?

[AndyBirtwistle]

In the UK we say,to save time.

[wolfe.mcbr]

It also sounds weird to an Australian. In context (like the professor example) i could figure it out but it sounds like a combination of different sayings into something 'unique'

[RickMcBrid2]

How about "on account of time..."