This year, CERN will be closed from Saturday, 21 December 2019 to Sunday, 5 January 2020 inclusive. The first working day of the new year will be Monday, 6 January 2020.

As is the case every year, the only persons who will be entitled to enter the CERN site during the end-of-year closure are those who have been authorised to do so for strictly professional reasons (stand-by service and indispensable maintenance work).

Each department and, in particular, each experiment’s technical coordinator, is responsible for compiling a list of the persons concerned by Friday, 20 December 2019.

Unlike in previous years, it is no longer necessary to include members of the personnel of outside companies in these departmental lists. Any members of the personnel of outside companies who are required to work on the CERN site during the closure must have a valid notice of work to be done outside normal working hours (AET). Please note that AETs must be limited to the time needed to perform the work in question or, in the case of annual AETs, must not extend beyond 18/12/2020. As a reminder, all 2019 AETs will end on 20/12/2019 at the latest.

During the period when the Laboratory is closed, i.e. from 21 December onwards, any personnel who need to enter the CERN site for an urgent reason and without the prior authorisation of their department or their experiment’s technical coordinator will be obliged to submit an access request (“CERNXMAS” permission request), which may be signed by the Security service or the CCC (TI) after its legitimacy has been assessed. The “CERNXMAS” permission option will not be available in the ADAMS system until 21 December. This provision does not apply to members of the personnel of outside companies, since they must have a valid AET.

We would also like to remind you that all CERN services (including the restaurants and the library) will be closed during the end-of-year closure.

We thank you for your cooperation and wish you all a very happy holiday!