My schedule changed 2 years ago when I had to start working early hours (market openings), rather than the typical late morning till late evenings.

I had the hardest time working on the staple dev diet (caffeine + sugars). Switched to low (well, none) carbs + 30 minutes of exercise before work, definitely changes how my energy flows during the day. Mornings are now extremely productive, peak at 4PM then downhill from there.