The date for the municipal elections is set by government decree at least 80 days in advance. According to municipal electoral law, these elections must take place between September 22 and October 14, and on a Sunday.

Minister António Leitão Amaro justified the choice of the date because it was the one most suggested by the parties consulted by the Government and indicated that there had also been prior dialogue with the President of the Republic, Marcelo Rebelo de Sousa.

On June 26, the government met with all parties in parliament about choosing the date for the local elections, with the majority preferring October 12.

On that occasion, PSD, Chega, PCP, PAN, Livre and CDS-PP indicated to the executive that they considered that the next local elections should be held on October 12, while PS and IL pointed to the date of September 28 and BE communicated in writing that it preferred October 5. JPP met with the Government but did not make any statements in the end.

According to municipal electoral law, these elections take place between September 22 and October 14 and on a Sunday, so in practice there were only three possible dates: September 28, October 5 (a holiday commemorating the Proclamation of the Republic) and October 12.

The last municipal elections took place on September 26, 2021, in 2017 they were on October 1, in 2013 on September 29, in 2009 they were on October 11 and in 2005 on October 9. Previously, municipal elections took place in December.