After downloading the aforementioned paper and uploading the to google translate, since I don't speak Swedish:
> Summary 18 months with 6 hours
> 6 hours of trial
> City of Gothenburg decided in 2014 to conduct a trial with 6-hour day with follow-up research. The trial started 2015-02-01 and 2016-12-31 terminated after 23 months. The trial will answer the question about the effects of reduced working hours have for nurses, tenants and the economy / jobs.
> The trial has been shortened working hours to 6 hours per day and 14.9 full-time employees, 17 nurses have been hired to compensate for reduced working hours. Consequential changes have made of schedule at Svartedalen center for the elderly. To provide a high comparability has no other changes made by different senior housing from others. In follow research studies 100 % Of nurses participated.
...
> There are 29 sessions on a six-week period in the new schedule. Three of the six weekends included. Employees at Svartedalen work in the trial between five and seven hours on daily schedule. In practice, between 6 hours and 6.25 hours (6 hours and 15 minutes). That it not exactly six hours per day due to scheduling must answer received business needs.
> Night schedule is at least six and no more than eight hours. Before the experiment was working nine hours on overnight.
So yeah, the resulting full-time hours were 30, but the study was specifically interested in 6-hour work days, according to the report. The only reason it wasn't exactly 6 was for business/logistical reasons.