Under the current rules, a PCR test must not be older than seven days or an antigen test not older than 72 hours. A test certificate from the employer or school, an affidavit from the parents that the child was tested at school, or an on-site antigen test will also be valid. Alternatively, proof of having recovered from Covid-19 within the last 180 days, or proof of at least 22 days after the first dose of vaccine may be acceptable.