From here you can check and update the official date and time
Article 26.5 of Law 11/2007, of 22 June, on citizens' electronic access to public services establishes that each electronic office in which an electronic register is available shall determine, according to the territorial area in which the owner of that office exercises its powers, the days that shall be considered non-working days for the purposes of the previous paragraphs.
Access to the working calendar of non-working days for the current year.
Article 26.1 of Law 11/2007, of June 22, on electronic access by citizens to public services, states that "electronic records shall be governed, for the purposes of calculating the time periods attributable to both the interested parties and the Public Administrations, by the official date and time of the electronic access site, which must have the necessary security measures to guarantee its integrity and be visible."
Likewise, Article 6.2 j) of Royal Decree 1671/2009 of 6 November 2009, which partially implements the aforementioned Law, establishes that electronic offices shall indicate the official date and time for the purposes set out in Article 26.1 of Law 11/2007.