When is the best time to exercise?

A workout is never late, nor is it early, it arrives precisely when it means to.

RIGHT NOW!!!!!

Is that specific enough?

The answer will be individual.

Sticking with one's exercise routine is the big deal. That makes preference (practicality, enjoyment, etc.) the biggest criterion for timing (as well as for location, exercise type, etc.).

Some considerations: Some people are too tired to exercise after work, so they prefer to get up an exercise before work. Some people work near a gym or other relevant place, so they exercise on lunch hour or right after work. Some people (I'm one) will do anything on this green earth not to get up any earlier than absolutely necessary, so prefer to exercise after work. Some people can't exercise right after a meal (because of digestive distress), so they time exercise away from meals. Some people can't exercise too close to bedtime (because it interferes with good sleep).

If you're not sure what's best for you, try various options and see which suits you best. There's no particular theoretical advantage that outweighs personal preference.

When I was working, I exercised after work. Now that I'm retired, I do on-water rowing in the morning (4 days a week in season) because the weather conditions are better then (wind is the main thing), but not too early because I still don't like getting up early. Other exercise I do later in the day, biking usually in the afternoon (still daylight), but in Winter usually my indoor stationary bike or rowing machine workouts are usually evening, sometimes late evening. Ditto for lifting (at home). In the rare case when I swim, I usually go to the pool during other people's working hours, or shortly before closing time, because I'm bad at sharing a lane. I can work out soon after eating (as long as I haven't totally stuffed myself), but for me (unlike some other people) fasted workouts feel miserable (and I underperform), so I don't do any significant workouts before breakfast if I can avoid it.

For me, during the week it's starting at 1pm since by the time I'm done there aren't many people in the locker room so I don't have to deal with maneuvering around people or stepping into gross showers.

During the weekend it's around 11am since several classes at my gym get done around 11 or 11:30 and they go to shower, and by the time I'm done the showers have been cleaned after the rush.

This is highly variable, and depends entirely on the specific gym.

I don't like to work out early in the morning since that is my most productive work time. Exercising in the middle of the day breaks up the day for me which helps me meet some of my other goals.

Anyone who tells you there's a single best time of day, for whatever reason, is over-generalizing the best time for them to all other people.

After work is what I do.

Why you ask? Because I can't get up before 5am and have to be at work for 6am... lol

Given a choice, I would exercise at 10am, with lunch immediately following. However, this thing called "work" keeps interfering with this plan, so I have to go either before or after. Given my work day plus commute get me home after 7pm most days, and my performance (and desire) suffer horribly at night, I choose to wake up at 4:30am and get my lift on then.

18:00. That's 2 hours after my dinner, I have masses of energy and not an overfull stomach anymore. Perfect.