Running an Armchair Marathon

The flag-waving, barbecue-grilling, fireworks-flashing Fourth of July holiday is here at last, a day set aside for feasting on all the traditions Americans hold dear. And for millions of our good citizens, what would the Fourth be without a gluttonous helping of vintage TV, with a veritable parade of marathons led by that grand marshal of the macabre himself, Rod Serling?

“You’re traveling through another dimension, a dimension not only of sight and sound but of mind; a journey into a wondrous land whose boundaries are that of the imagination. Next stop: ‘The Twilight Zone.’ ”

With those words, Serling will kick off a two-day string of some of the best “Zone” episodes, running from 7 a.m. today to 6 a.m. Saturday on the Sci Fi Channel. Only an hour of paid programming Friday around dawn breaks the spell.

The E! Channel has put together a marathon of its own, scheduling a block of “Saturday Night Live” shows from 9 this morning to 8 p.m.

But wait, there’s more: The Learning Channel airs consecutive episodes of “Junkyard Wars” from 1 p.m. today to 3 a.m., including the finale, “Junkyard Wars: Bloopers and Trashy Outtakes.” And the Animal Planet channel has “The Planet’s Funniest Animals” episodes running today from 6 a.m. to 7 p.m., capped by a special show featuring “Lilo & Stitch.”

Bon appetit.