Yes, the date is correct.
Gary The Rat began as an online series three years before it was picked up by Spike TV. In other words, series star and producer Kelsey Grammer began work on the series while still starring on NBC's Frasier and occasionally turning up on The Simpsons. Spike picked up the series in June 2003, and even though it was the best of the short-lived Thursday night animation block, Gary The Rat lasted just 1 season.
Knowing what we know now, it seems that the nimrods at [adult swim] had seen Gary online, and decided to rip it off, turning a 60's superhero into Harvey Birdman, Attorney-at-Law, which bowed a year or two after Gary. Spike then took a chance, hoping to siphon off some of [as]' audience. It didn't work.
Here's the initial installment, "Manrattan". As I understand, the 9 minute video represents the complete episode, even though it says "Part 1" on the title card.
Not even sure if this is available on DVD at present. It was fun while it lasted. Too bad [as] didn't learn from their fundamental mistake.