Brazil's legislature has voted to enshrine a 40-hour working week into the constitution, trimming four hours from the existing 44-hour standard, alongside a guaranteed two-day rest entitlement each week that workers will receive without any loss of earnings.

Covering more than 30 million workers — with those on six-day schedules standing to gain the most — the measure has been characterised as the largest shift in working-hours rules since 1988, based on reporting from a broadcast news outlet.

The bill gained the force of law after senators approved it 75 to 1 on Wednesday — it had already passed the lower chamber in May — with the vote coming several weeks ahead of the 25 October presidential run-off between Luiz Inácio Lula da Silva and Flávio Bolsonaro. Drawing 47% of the vote in the opening round, Eduardo Bolsonaro — whose father, Jair Bolsonaro, once held the presidency — edged ahead of Lula, who pulled in 45.2%.

Bolsonaro cast a vote for the reform despite having taken an opposing position on it beforehand, telling reporters that the majority of Brazilian workers wanted the six-day workweek brought to an end, which was why he had decided to support the measure. Prior to this point, he had described the proposal as an election tactic driven by political timing rather than genuine policy need.

Lula characterised the shift in his opponent's position as a move driven by electoral calculation rather than genuine conviction. Lula expressed support for the amendment, noting in a social media post that it would give people greater opportunity to step away from work — affording them, in his words, more time for rest, family, watching their children grow, personal wellbeing, and enjoyment of life.

Phased implementation is planned for rolling out the reduced working week. At the two-month mark, the weekly ceiling drops to 42 hours, with a further reduction to 40 hours taking effect after an additional year.

Lucinda de Almeida, 36, works a checkout till at a Rio de Janeiro supermarket six days a week while raising three children without a partner. Speaking to a well-known broadcaster, she described the proposed change as one that would matter considerably to her, given that her single day off each week tends to disappear into household duties, leaving both her body and her mind drained of energy — time she would rather spend with her daughters, pursue leisure activities, or simply rest at home.

A nationwide poll found that close to seven in ten Brazilians backed a shorter working week. Those backing the proposed changes argue that workers nationwide stand to gain a healthier balance between their professional and personal lives.