• Meta CEO Mark Zuckerberg has done an about-face on remote work.

• The company is putting in place detailed and mandatory rules for in-office and remote work.

• See new rules on badge tracking, monthly evaluations, and remote workers only allowed in-office a few days per quarter.

Meta founder and CEO Mark Zuckerberg used to say remote work was the way of the future. Now, he's implementing an aggressive return-to-office mandate.

The company formerly known as Facebook on Thursday laid out for employees its updated policy on RTO – or what head of HR Lori Goler referred to in a note as its "In-Person Time Policy" – to take effect September 5, as Insider first reported.

Meta initially revealed to workers in June that it planned to have people back in the office this year at least three days a week.

Under the new guidelines issued Thursday, Meta made clear that office attendance is strictly mandatory for everyone that is not approved for fully remote work. Workers need to be in their assigned offices most of the week.

They will be monitored by their managers and have attendance tracked by the company. Those who flout the new rules risk "termination," or being fired, Goler's note said. It could also impact their performance reviews, which have already become harsher.

Meta's RTO policy is now as stringent as Amazon's, which has taken a very firm stance on people returning to the office. Under CEO Andy Jassy, Amazon is also forcing people back to work in their assigned office at least three days a week, despite having no data to back up the move. Google has also said staff who don't work in-office at least three days a week could see their performance reviews impacted – a move that has frustrated many employees.

Zuckerberg himself this year has emerged as a more hardened and Wall Street-appeasing CEO. His public discussion of the metaverse has turned away from an initial desire for his ambitious virtual world to bring about a new era of remote work.