Twitter staff have been told to work 84-hour weeks and managers slept at the off...

• Twitter managers have told some staff work 12-hour shifts, seven days a week, CNBC reported.

• Some managers told The New York Times they slept at Twitter's office on Friday and Saturday nights.

• Staff are trying to prove themselves amid the looming threat of layoffs under new owner Elon Musk.

Staff at Twitter have been clocking up much longer hours than usual since Elon Musk took over, CNBC reported. This comes as staff face the looming threat of layoffs amid the tech mogul's planned overhaul of the company.

Twitter managers have told some staff to work 12-hour shifts, seven days a week — equivalent to 84 hours a week — to meet Musk's deadlines, CNBC reported, citing internal communications.

Musk's $44 billion purchase of the social-media platform went through on Thursday evening, but concerns about layoffs at the company have been swirling since well before that. It remains unclear how many staff will be laid off and when, as well as which teams will be most affected.

Since Friday, staff at the company have been set tasks which some see as a test by Musk's team to see who works hard.

Insider previously reported that Musk's team assigned some of Twitter's engineers coding projects to work on over the weekend, known as sprints. Other tasks include making major changes to Twitter's verification service.

Insider previously reported that an internal message was sent to Twitter staff working on changes to the company's verification process telling them that: "The expectation is literally to work 24/7 to get this out."

CNBC reported that staff haven't been told whether they'll get overtime pay, time off in lieu, or job security for working on the assignments.

Staff worry that their careers at Twitter could be over if they don't complete their tasks by the early November deadlines, CNBC reported.

Twitter's managers, meanwhile, have been asked to carry out performance reviews and send Musk's team lists of which employees should be kept on, people familiar with the discussions told Insider.