Twitter Inc (NYSE:TWTR). staff will have to burn the midnight oil if new boss Elon Musk gets his way.
Musk has told staff that they must commit to working "long hours at high intensity" or else leave the company, according to reports.
In an email to staff, the social media firm's new owner said workers should agree to the pledge if they wanted to stay, the Washington Post reported.
Those who do not sign up by Thursday will be given three months' severance pay, Musk said.
In the email, also seen by The Guardian, Musk said that Twitter "will need to be extremely hardcore" in order to succeed.
“Going forward, to build a breakthrough Twitter 2.0 and succeed in an increasingly competitive world, we will need to be extremely hardcore. This will mean working long hours at high intensity. Only exceptional performance will constitute a passing grade,” Musk wrote.
Workers were told that they needed to click on a link by 17:00 EST on Thursday, if they want to be "part of the new Twitter".
He added: "Whatever decision you make, thank you for your efforts to make Twitter successful."
The world's richest man has already announced half of Twitter's staff are being let go, after he bought the company in a $44 billion deal.
Musk said he had "no choice" over the cuts as the company was losing $4 million a day.