does/did

[idiotmike]

Here is a reading from the Economist, the author use the following sentence to end the article. My question is why uses “did” instead of “does”?
Assuming he keeps his job till then, it is time he did something useful.
Thank you very much.

[emsr2d2]

Here is a reading an excerpt from The Economist. The author uses the following sentence to end the article. My question is why did he uses use “did” instead of “does”?

"Assuming he keeps his job till then, it is time he did something useful."

Thank you very much.

Please see the few amendments I have made to your post in red.

The phrase "It's time somebody did something..." is a common one and whilst I can see why you might expect it to be in the present tense, it's actually correctly written.

The phrase "Assuming he keeps his job till then..." is an example of the present simple being used to express the future, by the way.

"It is time..." refers to the present.

"...he did something useful" as I said is a common expression.

The writer is saying that the time has arrived for the subject to do something useful. I would assume that he has been in his position for quite a long time and has not done anything useful yet.

It's time you went to bed.
It's time he got married.
It's time they drank all that wine.

[allenman]

Here is a reading from the Economist, the author uses the following sentence to end the article. My question is why uses does he use “did” instead of “does”?

Please try subject-verb matching when asking your questions. I am not compelled to answer your question when you do not take the time to assemble your question correctly.

Not a teacher -- AmE native