Before I retired, I worked for a very large employer and was not unionized, basically because there was no reason to unionize. It isn't as though the workplace was perfect: There definitely were some things that were less than ideal but all in all, as far as how workers were treated, it was extremely fair and actually generous. Being such a large work place, it was broken down into hundreds of work units. Certain aspects of the job were left to individual workplaces to decide. Scheduling was one of those. Because it was health care, we worked holidays and holiday weekends. I know that some work units organized that strictly on seniority. Mine did when I first started working there but then they switched to a rotating schedule so that various holiday shifts were sorted into sets. In turn, each employee chose which set of holidays/holiday weekends they would work. The first year, this was strictly on a seniority basis BUT once you had your first pick, you moved to the end of the line. This worked extremely well. We were also allowed to trade weekends/holidays with each other, so long as everything was covered. It was fair and just. As time went on, people were more cooperative with one another, and much more willing to trade weekends or holidays to get a weekend off for a wedding or special event, or whatever. People who were normally fairly contentious with one another saw the benefit of cooperating and working towards the benefit of all parties.
BTW, I had to thank for this bit of justice the group of younger employees who were more interested in a healthy work/life balance, or at least who felt more entitled to work towards than rather than simply accept the status quo as all of us old farts did, grumbling to ourselves and letting our dissatisfaction grow.
