G: TL;DR: Yes, full spectrum LEDs can support plant growth. They don't need ultraviolet light, but they do need blue and red wavelengths — both of which are part of the visible spectrum and typically included in full spectrum LEDs.

Expanded:
Plants mainly use blue light (~450 nm) for vegetative growth and red light (~660 nm) for flowering and photosynthesis. UV is not essential — some plants can benefit from small UV amounts for stress responses (like color or flavor development), but it's not required for general growth.

If your full spectrum LED is designed to mimic sunlight (common in grow lights), it’s likely fine for most houseplants. If it’s just marketed for room lighting, it might help a little, but won’t be optimal — especially for light-hungry species.

If you're curious, I can help you check your LED's spectrum based on the model or box info.

M: Maybe next time. Honestly, it might be better if it only provided a little bit; I was wondering because I have a basil plant, and if I understand they’re not supposed to be in full lighting. I tend to stay up late at night, and I was wondering if I was screwing with it Growth cycle or something. Do plants – either all of them, or some of them – require or do better with a day/night cycle, or can they just deal with light 24 seven?

G: TL;DR: Most plants, including basil, need a day/night cycle to grow properly. Continuous light can stress them or mess with their internal rhythm. You're not wrong to worry about it.

More detail:
Plants have something like a circadian rhythm called a photoperiod — they evolved to expect periods of light and darkness. Basil is a long-day plant, meaning it thrives with about 12–16 hours of light, but it still benefits from 8–12 hours of darkness for rest. Constant light can cause issues like stunted growth, leaf curling, or weird pigment changes.

If your room light is on late at night, it probably won’t kill the basil, but it might slow growth or make it leggy (stretching toward stronger light). You could loosely shield it from late-night light, or just set a regular cycle using a grow light on a timer if you want to be precise — but honestly, even a few hours of darkness helps.

Want a quick trick to gauge if your setup is bothering the basil too much? Watch for upward curling leaves, very pale new growth, or a strong lean toward windows/light sources — those are good plant "tells."

M: There’s no upward curl, and the new growth is normal. How long does it take to develop a “strong lean“? Because I have noticed that they leaned towards the window I put them next to – not indirect sunlight, but within the corona – in such a way that about once a month it’s noticeable and I rotate the pot to keep it from becoming permanently slanted.

G: That sounds totally normal. Plants like basil can start to show a noticeable lean within a few days to a week if the light source is stronger on one side — especially if it’s the sun, even indirect or glancing exposure.

Your habit of rotating the pot monthly is solid — that’s actually what commercial growers and greenhouse operators often do. The lean you’re seeing isn’t a sign of stress, just phototropism (plants turning toward light). As long as new growth is healthy and the plant isn't visibly stretching (long internodes or pale stems), you're doing fine.

Basically:

No curl + normal color = not light-stressed.
Monthly lean = normal phototropism.
Your basil is behaving like a basil should.

If you ever wanted to go hands-off, a timer-controlled grow light near the plant would give it a more consistent cycle, but it’s not necessary if your current setup works and you’re already paying attention.