in connection with a new government measure we would like to inform you that an employee who must complete a form on return to the Czech Republic and who must have a test (or take one within five days of returning) also now has the obligation to inform the employerthat he or she has been outside the Czech Republic for more than 12 hours (in some cases 24 hours). 

Employers must not allow employees into the workplace without a negative Covid 19 test result (this does not apply to people who have had Covid 19 in the last 180 days and those who have been vaccinated in an EU country and at least 14 days have passed since the complete vaccination).

This test is not administered by the employer. The employee must submit the results of the tests required to cross the border when returning to the Czech Republic, which are only tests performed by a medical facility (not self-tests). Submit the certificate to the school secretariat.

More information can be found here: https://covid.gov.cz/situace/zahranici/mapa-cestovatele-podminky-vstupu-do-zeme-povinnosti-po-navratu-do-cr