Security guards, nurses, stock clerks, and janitors—just some of the roughly 28 million people who earn a living working odd hours, mostly nights and weekends, outside of the traditional work schedule. They’re often “invisible to daytime workers,” even though their work is vital to the economy, Maria Enchautegui writes in “Nonstandard Work Schedules and the Well-Being of Low-Income Families,” a look at the challenges nonstandard work hours place on low-income families.

Enchautegui answers our questions about workers on nonstandard schedules and how government and employer policies can better reflect their needs.

1. Who works nonstandard work schedules?

I used a very conservative definition of workers in nonstandard schedules, counting anyone who works weekends or from 6 p.m. to 6 a.m. on weekdays. I found that one in every five workers has this sort of nonstandard schedule. Lower-income Asians are most likely to work nonstandard schedules, but black workers tend to stay in these jobs even at higher wages. That black workers don’t move out of these jobs may speak to labor market limitations.

I was surprised to see that, for most workers on nonstandard schedules, these jobs are full-time jobs and their only job. That doesn’t match up with the common thinking. People think workers choose these jobs because they want to go to school during the day, or be with their kids, or because they like to work at night. But, in reality, people take these jobs because they’re trying to support their families and these are the only jobs available.

2. What kinds of jobs require odd hours?

Most are low-wage jobs. You can see that in the types of occupations and industries with high shares of nonstandard schedules. Security guards and gaming surveillance officers, for example, often work outside the traditional work week, and their median earnings were $519 a week in 2011.

We also see that occupations with the highest share of nonstandard schedules are projected to grow the most over the next 15 or 20 years. Registered nurses, home health aides, and personal care aides—all of which have high shares of nonstandard schedules—are among the top four growing occupations.

3. What difficulties come with working nonstandard schedules?

The world of work is totally organized around an 8 to 5 schedule. If you don’t work that schedule, you may have more problems performing your job. For instance, child care centers usually close around 6 pm, so these workers need to come up with other arrangements for evening and weekend child care. Or take public transportation—in DC, Metro closes at midnight on weekdays and buses run at reduced times. Metro is open later on the weekend nights for the party crowd, but not on weekdays for the labor crowd.

Another problem is accommodating emergencies. A lot of these jobs don’t offer paid leave and workers don’t have a lot of flexibility in their schedules. Night-time schedules are usually staffed at a minimum, so it’s not easy to take time off and have someone else pick up your shift. Also, if these workers have a problem with payroll or accounting, they have to come in during the day to meet with other staff.

But perhaps the most difficult challenge is how to spend time with your family. How do evening and weekend workers find time to spend with their children? We found that parents with nonstandard schedules spend much less time with school-age children than parents working traditional work schedules.

4. How can policymakers and employers respond to these difficulties?

I think these workers are overlooked. We don’t think about them. If you look at the Fair Labor Standards Act, which guides our wage and hour regulations, it talks about an eight-hour day but doesn’t say when those eight hours should be worked. What if you work a night shift? The law is mute in that regard, ignoring a huge number of workers.

Government, employers, and schools can all respond. Policymakers should think about promoting the creation of child care facilities with odd hours, perhaps through incentives in areas with a lot of nonstandard-schedule work—for example, in areas with a lot of tourism.

Meanwhile, employers can provide paid time off for vacations or sick leave. Even making scheduling changes so workers have one weekend off a month would help a lot, allowing these workers to spend time with their children.

Schools also can accommodate the needs of parents who work nonstandard hours. They should be aware that some parents can’t participate in school activities during traditional “after-work” hours and try to find other ways for these parents to get involved.