FXX enjoyed the most watched day in its one-year history with the first day of its The Simpsons marathon. Not surprisingly, the 12-day marathon — featuring all 552 Simpsons episodes plus The Simpsons Movie — scored its best numbers so far in primetime Thursday, netting slightly more than 1 million viewers, including 623,000 in the demo. For comparison’s sake, FXX has averaged 206,000 primetime viewers since its launch on September 3, 2013 — and 111,000 demo viewers.

With Day 1 of its orgy of Simpsons excess, FXX ranked No. 1 among all basic cable networks in primetime with men 18-34; it ranked No. 2 in adults 18-34 and No. 5 in adults 18-49.

The most watched episode of Day 1: 8:30 PM’s “Itchy & Scratchy & Marge,” which topped the day 1.23 million viewers – 749,000 of them in the demo. That episode also was the network’s best performer yesterday in the 18-34 demo and ranked No. 3 among all television programs for the night in that age bracket. Among 18-49, it ranked No. 11.

In its news release about its numbers, FXX took a moment to acknowledge that, yes, FX Networks had said the company would no longer issue Live+Same Day numbers because those numbers are pure horseradish in this age of so much delayed viewing. Here’s how FXX explained this apparent about-face: