If you want to grind coffee beans into code, then buy a “programmer”. If you work at an internet company full of coding masters, ask those programmers around you when their efficiency is highest and ideas best — most answer late at night, whether the first or second half. 
Surely many are curious and can’t understand why this group doesn’t work during the energetic daytime but stays up late at night. I also read several viewpoints online, and combined with myself, let me talk.
- Afraid of being disturbed and losing the thread Speaking of fear of disturbance, I think most would say this reason, which is why programmers get unusually angry when interrupted. For this reason, they usually start working only when sure of several uninterrupted hours. A good analogy: the process of creating or programming is like building a house with expensive and fragile crystal; once someone disturbs you, all your effort may be ruined, and all the sweat poured in may shatter instantly. During the day there are many things to do — constant interruptions, many important things to handle, emails to reply, etc. — all disrupt your rhythm and prevent focused work. At night, the wife and kids sleep, the product manager gets off work, and you have several consecutive hours entirely your own, to do your own things and let the thread continue orderly.
- A tired brain keeps attention focused The second reason is the same as the first — it makes you more focused. Similar to the Ballmer effect, tiredness makes the programmer more focused, because with a tired brain you must focus very hard on one thing. Your remaining brain capacity isn’t enough for extra things, so you can only focus on the task at hand. During the day, full of energy, after too much tea or energy drinks, efficiency is lowest — you check QQ, Weibo, forums, attention hard to focus, because your brain is excited, which is bad for sitting down to think.
- A bright screen pushes the biological clock later This is a biological issue. If you keep staring at a bright light source, the sleep cycle shifts later, so even at 3 a.m. you don’t feel tired. And when night comes again, you don’t feel tired either, because you got up at 11 a.m. It’s like living in another time zone; more interestingly, once you get used to this schedule, it’s hard to go back. From the three points above, night has quieter and more relaxed time, the brain isn’t disturbed, and the bright screen keeps you more alert — exactly what mental workers need.