Facebook announced that U.S. employees will not return to the office until at least January 2022 due to concerns about the coronavirus delta variant. “Data, not dates, is what drives our approach for returning to the office,” Facebook said in a statement. The social media company is the latest among tech giants to delay returning to the office to fall 2021 or 2022. Upon return, Facebook and Google will also require proof of vaccination, but both said implementing the requirement will depend on local guidelines.