I guess I'm a bit backwards to many of you. My UVB and K6500 t5 come on first by 30 minutes. I was thinking of imitating the heat cycle rather than the UVB cycle. I was hoping to get them started on UVB for the day before they gravitated to the basking lamp. UVB and plant are last off as well.
So my way, has been more focused on trying to intimate nature. To a degree.
The reason that our Morning sun is so Low K (2700-3000) is that Red light carries further than that of other spectrum. The first rays you see during a sunrise, is red light mostly, including infrared (Heat). As the sun gets closer, and better angled, the blue light begins to come through. As we move further, into the day the UV Rays (shorter than Blue) begin to come in.
So in a real sun light, we have Red mornings, into bluer midday with strong UV, back into red nights. (super simplified, there is alot more going on, but thats the simple version for this thread)
Now you do have a good point, that its also natural for heat to rise as the day progresses. This will be influenced mostly by your heating/cooling as well though.
Its a blessing and a curse, that AC doesn't work too well where I live. We use Propane Heat (so sporadic) and Evaporation Cooler (so Sporadic). My house gets hotter as the day progresses, in the winter it does because we keep the stat lower than a warmth of the day rises it, and the Thermometer for the Propane heat is in a hallway thats cooler, than the room with the chams that gets midday sun on the large windows heating up.
The Cooler in the summer simply cant keep up, so it gets warmer as the day goes. Same as in winter, but in a bad way lol.
My LEDs also add heat into the viv, a more top side ambient, but noticeable.
So my end goal, is dimming all around, Dimming Halogens in the morning on, to provide red mornings and then the 6500k leds will start, to balance the day, then the 8400k (our UVB bulbs are 8400k) will give a further rise in spectrum. Then I will dim all it all down in reverse. Im just trying to get all my ducks in a row, and make sure I have an easy to recreate system as a finished job, so I can share it here.