At what time of day did you spray? It is best to apply or spray any pesticides very early in the day so that the foliage has time to dry before the heat of the sun hits it. Sun and pesticides together can often result in a phytotoxic reaction that can damage foliage.

Might be leaf spot (Septoria). If so, fungicides could protect healthy leaves. Septoria happens in warm, wet conditions. So if you're spraying leaves a lot, and keeping them wet, that could encourage it.

I sprayed early morning around 7 am and on an overcast day.

Your leaf damage is on the lower part of the plant, on leaves that might be shaded. So I don't think we're looking at phytoxic reactions. I'd expect to see such reactions on the topmost, most exposed leaves. Leaf spot usually happens on the lower leaves, because those are usually the moistest, and closest to the soil, where the fungus is picked up.

Yes, early morning or overcast spraying is unlikely to be phytotoxicity.

What are my next steps? Prune off the damaged leaves. Spray a mixture of Daconil and Neem oil tomorrow morning? Spraw Daconil tomorrow morning. Then Sunday spray with neem oil or in reverse?

If you don't have insect pests, and don't mind using Daconil, why bother with Neem? If leaf spot, then certainly get rid of the damaged leaves. I've never been convinced that Neem is a particularly good fungus killer, except maybe in high concentrations. Of course, it does kill insect vectors, if that's how the fungus is being transmitted. In general, I believe the way horticulural oils work as fungicides is just sealing off the surface of the foliage, making it impenetrable to fungal spores.

Be careful. I don't think horticultural oils play well with sulfur-based fungicides. I believe Daconil is not one of the latter.

I was using neem oil for spider mites and whiteflies. A lot of my plants have so many spotted leaves from them.

Not many fungicides are "good fungus killers" - the vast majority are only preventative, not curative. Daconil/chlorothalonil would be included in this category. Neem actually has systemic properties so has the potential for being even more effective as a fungicide (and it does have defined fungicidal properties over and above just being a horticultural oil).

That's true about most fungicides being preventatives. But when I see extension services suggesting (among other things) Neem as a fungicide, they talk about spraying 70% solution. As in, undiluted. That's powerful stuff. As a pesticide, highly diluted Neem works fine.

My very first experience with neem oil was with Green Light's Rose Defense RTU spray more than 20 years ago. Now discontinued under that label, it was only a 0.9% concentration but still had pretty impressive fungicidal properties.

The 70% concentration recommends using 2 Tbsp (1 ounce) per gallon of water for use as a fungicide. That is a pretty sgnificant dilution. And this is the same with various vendors. I don't see anywhere that they suggest using full strength..........

Purdue Extension recommends spraying 70% Neem oil for fungicidal effect. You can get 70% Neem ready-to-spray bottles for that purpose. But in order to use it as a pesticide, high dilutions are effective.

https://www.extension.purdue.edu/extmedia/bp/bp-69-w.pdf