This article may help. It basically gives the pros and cons of Hiit and Steady State, then you make your own decision. Based on what works for you and your life. It doesn't really talk about morning or evening, but again, that's your decision.
https://www.cellucor.com/blog/cardio-throwdown-steady-state-vs-hiit
Here's another article to throw in the mix:
https://experiencelife.com/article/steady-state-cardio-vs-high-intensity-interval-training/
and an article from Cathe:
http://cathe.com/which-is-better-for-weight-loss-hiit-tabata-or-steady-state-cardio
I liked the first article a lot. I agree with the conclusions: do the cardio, types, frequency and intensity that you enjoy, can sustain and that pushes you that little bit each week to make the best version of you and to be happy, with boundless energy. In comparison to the author's preferred cardio, for me that would be lots of walking, some steady state step, metabolic workouts and one HiiT session per week. But, that's me. You figure out what you like and what suits your body and also your brain. I never underestimate that: my body might benefit from 3 * HiiT per week, but it would cut into my walking time and the walking time helps with my mental health.
How about you? What do you need and prefer? What do you need to function optimally? Also, how much time do you have? A short 30 HiiT session may be all you have time for one day, and on another day, you can luxuriate in a 60 min step session with Cathe. You decide.
I do disagree with this author on one point however, as do sports physiologists. Running is no harder on the joints than those 3 sessions of high impact HiiT. The high impact of running is good for joints, it strengthens bones and reduces your risk of developing osteoarthritis. You can see just as many injuries with negligent and excessive participation in HiiT sessions as you can in long distance running. Where running leads to injury comes from a) running is movement along one plane and produces repetitive force on the same muscles/ligaments and tendons, b) muscle imbalances and areas of weakness in the muscular structures. If you have a weak area, say, the hips, other structures are forced to step in and do the work the hips should be doing, thus taxing these other structures (the ITB, the ligaments around the knee that affect patella tracking, the achilles tendon, for example) beyond their abilities. Voila, you get injured. Running gets negative press for high incidence of injury but it's not the sport per se that causes it, rather the repetitive motion. The same can be said of high impact HiiT.
As far as timing of these workouts is concerned, I am not sure what your concern is? Some say that high intensity exercise within an hour or two of bedtime can make it hard to fall asleep as the endorphin high makes you energetic rather than sleepy. Personally, I'm a night time person and my energy levels increase as the day goes on. Optimal time for cardio for me is anywhere from 5 pm to 2 am. Others can do HiiT at 5 am upon waking. Any cardio within 2 hours of waking would kill me!
Other than that, I don't know what your thoughts are with this question. Any more info you can give us?
Edited to add: that second article is PHENOMENAL. There's great information about how different types of cardio training affect the heart that I had not known. Thanks for posting!
Clare