More completely the 8 hour work day movement. Loosely, 8hrs each for work, sleep, and everything else with everything else often being called recreation. Add in a 5 day work week and 40hrs. There's monument in Melbourne commemorating stonemasons winning an 8 hour work day in 1856 but they were working 6 days a week.

More specifically than Unions, it was the threat of violence (in extreme cases) and work stoppage by workers against the ownership class.

E.g. the Russian Revolution (one of the main workers' requests in the events leading up to the Revolution was the 40 hour work week and fair treatment).

The unions were just a symptom to mediate the threat of violence in exchange for a larger share of the added value generated by the worker.