She says she'll come, but I can't nail her down to a specific time.

她说要来，但我无法让她敲定具体什么时候来。

《牛津词典》

By contrast, the audience encounters an opera or a play over a specific time, which is the duration of the performance.

相反，观众可以有一段具体的时间来欣赏话剧或者戏剧，这段时间就是表演的持续时间。

youdao

The project must be completed within a specific time span.

这项工程必须在规定期限内完成。

《牛津词典》

The G20,which includes major industrialized powers in the Group of Eight plus developing nations with significant economies such as China and India, agreed to a specific time line for deficit reduction, while giving governments flexibility to adjust the pace of changes based on their own situations.

VOA: standard.2010.06.27

So,yes,there is a threat particularly of the use of radioactive material, although we have no specific evidence indicating any capability at this time."

VOA: standard.2009.05.01

"This is a time where business community looks for specific concrete moves by the government so that we are able to build confidence and bring confidence back to the system and at the same time we'll be able to help promote more trade and investment,".

VOA: standard.2009.11.11

Rather than calling at a specific time, this Santa, based in Colorado, gives a half-hour window.

WSJ: Comparing Santa Video Chats

Ministers have given back millions because their departments cannot spend it within a specific time period.

BBC: Stormont ministers criticised over ?42m in unspent funds

Out of randomness alone there will always be some category that outperforms over a specific time period.

FORBES: Indexes Beat Active Funds Again in S&P Study