For some people, the weekend is a chance to escape from work: for some it might be a chance to escape into work. The weekend is not synonymous with time off or time to relax. Families often do more in a weekend than they do in the other five days of the week put together!
There is no necessary value in taking two days away from work each week. There is some value in noticing that weeks (unlike days, or lunar months) are made for people, and require that people make use of them. Whether or not you notice, one day ends and another begins. Whether or not you notice, the moon will go through its phases and the seasons will change. Weeks only change when we allow them to change.
We sometimes work "for weeks on end" and we all remember the endless summers of childhood, when there was no school "for weeks on end." Life flows differently when there is no difference from one day to the next, when weeks don't end and begin but blend into one another in a steady stream. As we grow accustomed to the flow, we resist change in pace or direction.
Consider the cost of that. Whether you have taken weeks away from work or put many weeks in a row into your work, you have stepped out of a pattern that makes it natural to change pace or direction. When you next try to change (whether to return to work or to turn to play) you'll likely find yourself rusty and stiff. One way to keep yourself loose and ready for change is to mark the ending of each week, even when it's not the ending of work.
Today is Friday. What will you do today that puts closure to the week? Do you have a ritual that allows you to notice how far you have come since last week? It's useful to take a moment and think through the patterns that emerge over a week. It's the right amount of time to take you out of the mood swings and accidents that can colour just one day, and still see clearly the details of your choices and their impact in the world.