Hey William. For context, this answer is coming from someone who has really only been collecting daylilies for 5 years. I'm in a borderline 5a/5b climate.
I think "rebloom" has a couple meanings that get used interchangably, so I've learned not to trust that it means what I expect it to mean. When I think of true rebloom, I think of my clump of Stella blooming for a month in June/July, and then sending up straggler scapes again starting in mid or late August that can keep coming though frost.
But I think it's also commonly known as "rebloom" if your clump of daylilies has 8 scapes when it starts blooming in July, and by the time it stops blooming in early August, it has built 6 more scapes, so you finish with 14 used scapes. Sometimes I've heard that referred to as "instant rebloom". Which is a fine quality in a plant. Anything that helps get the most color out of a daylily each summer is great by me. But it's not what I think of as traditional "rebloom", and if you see a plant listed as "reblooming", well, what exactly do they mean?
If you're looking for trustworthy daylilies that will bloom early, and come back later in the summer/fall, I'm still trying to build that list myself. The ones I know work most years are Going Bananas, Happy Returns, Early and Often, Stella's Ruffled Fingers, Black-eyed Stella (just a great, great plant for me), and then, Chang Dynasty reblooms for me consistently, too. I want to find more like Chang Dynasty, that work here, but you don't hear about them, but it's a slow, trial and error, method. It's literally faster for me to breed new rebloomers for me. I've bred 4 or 5 in the time it took me to find Chang Dynasty. My favorite "instant rebloomer" is Dyna Girl from Paul Owen. A lot of its instant rebloom scapes produce poly and double versions of its bloom for me. And when it gives me instant rebloom, instead of 4 weeks of blooms, I get 6 or 7.
A great way to add to that list of DL's that rebloom in your region is to go to last year's "August Blooms" thread and look for people posting from your zone or region. Most things posted late in August are either Late bloomers and Rebloomers.
Otherwise, it's hit and miss for me. Last year I got rebloom scapes from Rambunctious Rosie and Bamboo Blackie for the first time. Seems like every year I get surprise scapes from plants that are probably pretty consistent rebloomers down south. But not too many I can count on every year.
