You don't have to be a church-goer to recognize the value of having A Day Off -- at least one Day of Rest per week.
This has nothing to do with Religion, everything to do with maintaining total, holistic Wellness--the precious synergy of Body-Mind-Spirit. Even the self-identified atheist can surely affirm that everyone needs a mental health day.
Sundays for Everyone
It's not enough to take a day off now and then, on your own -- you deserve to have at least one day each week that you can plan on using any way you want -- a free day that is common to everyone you know. So you can at least have the potential of planning a get-together with the people you love.
I don't care how you choose to spend your day -- it is entirely up to you. You can do anything you want with your Sunday -- but first you have to get it back.
We Sold Out Our Sunday
America had a day like this for a few hundred years, but we gave it up too easily. It seems the loss of Sunday coincided with the proliferation of the ATM -- the Automatic Teller Machine. Prior to that, the world still went round just fine -- if you needed cash for the weekend you simply withdrew it on Friday. Our desire for personal [selfish] 24-7 convenience dismissed the value of other people's time.
Somebody somewhere -- tons of people, actually -- has to work an 8 hour graveyard shift just because you might need a candy bar, a pack of cigarettes, or a gallon of milk at 2am. These are mostly items you could've anticipated needing and purchased ahead of time -- or things you can probably survive without for the next 12 hours.
Your money talks -- tell it to shut up on Sundays. If no one spent money on Sunday, most businesses would conclude that it is simply not profitable to be open on Sunday.
As with Free Speech -- or with any freedom, for that matter -- you protect your own freedom by protecting the freedom of others.
You can contribute to the movement to Take Back Sunday by simply refraining from spending money on Sunday. Willfully choose to believe and to behave as if commerce absolutely cannot occur on Sunday. Pretend everything is closed on Sunday and ruthlessly behave accordingly. Encourage everyone you know to do the same.
Don't try it -- do it. This is called manifesting.