Yeah...the twenty year olds are depressed. That isn't an indication of a mental health problem, that is an indication of an accurate understanding of the current world.
If you work a full time job, 5 days a week, 52 weeks a year, that's "only" 260 days. Assuming no holidays or vacation days. 71.23% of days.
Maybe they meant hours? No, that can't be right... 365x24 = 8,760 hours a year. If you work 8 hour days, 260 days a year that's 2,080 hours or 23.74% of available time...
In order to be working "80% of your days" that would be 292 / 52 = 5.62 days per week. So an extra half day a week, every week for a year, with no time off other than weekends.