Some jobs by their nature allow for more flexibility in work hours than others. What kind of work do you and other non-developers do in the company? It might help in determining why other areas of the company are more restrictive.

Spend two weeks finishing after midnight because of a strange unknown non-documented hardly reproducible bug coming from a good-to-have need realized by an other developer and then you will understand. The overhours are not paid obviously.

Seems that this is a question that can be answered by asking some of the people involved.

@TomTom : the funny thing is that it's usually the type of people that arrives at 9:30 and leaves at 18:30 sharp even if there is still a lot of work to be done that ask this kind of question. They also tend to do dramas when they have to do afterhours

Usually in my country (France) we get paid for day of work, not hours of works. This allow flexible time.

Also keep in mind that in some countries (especially europe) demand for developers is so high, that giving them lots of slack keeps them from switching jobs. (So demand issue in that case)

@MathijsSegers : per experience, everyone has different efficiency/focus time spikes. Some people will be more effective from 10a.m. to mid-day whereas others will rock from 6p.m. to 8p.m. . A good dev knows his spikes and adapts his day accordingly (as efficiency & optimization is part of our DNA).

@Answers_Seeker Your comment is a microcosm of an entire industry that needs to change and meet modern employers rights. Unpaid overtime should never be expected and workers should (and do in many companies) have a right to refuse to work it. Work life balance is important.

@Smeato: It really depends on the company and, in my former case, the project you are staffed in. Company-wise, It's expected that you exceed your objectives in order to climb the ladder and need to do more than just doing your work hours and your duty to give a good corporate image (exception in Germany from what I've heard). Project-wise, all must delivered on-time so you end up sometimes doing more helping other devs or making the wordload fit the impossible deadline. However, you get paid sometimes like for this Easter 2016 Week-end during which we spent 38 hours in 2 days working :)

In my company most of the devs are at the office at 7:30AM an leave near 4:30PM. We could arrive 1h later, but most of us like having some free time in the evening, especially during summer so we can enjoy the sun outside.

@Tim It was the case in another I knew but it was high-tech civil service with made off army veterans. I'm quite sure my experience was really specific.

Work from home for developers is much easier than you think. We can develop code literally from any device, from any place at any time. Whenever I feel "I go it!", whether it was 3 a.m or 10 a.m, I go and put it together and move forward. Developers are not "Code monkeys" to just sit and do coding, who do you think does the thinking behind/before the coding?

This might not happen in countries like Italy: national regulation dictates working hours and the possibility to apply flexibility depending on your role ("contract level"). Employees do normally work 9-13/14-18. Managers may have certain level of flexibility. Excecutives do not have generally working hours and clock-ins. First application that comes in my mind where work hours matter: workers benefit from government insurance against injuries during the home-office commute, and being in the street at 9:15AM can at very minimum result in investigation and questions (one's to justify)

@ThePassenger do you know when the dev teams leave? In my company, we sometimes do releases in the evening when most users are already gone, which works nicely due to the shifted working hours.

I know it's not an answer to your question, and it's not representative of all dev teams, but my team usually arrives to the office between 7.30 and 8.30 every morning. Not that we have to or even if it's necessarily preferred or looks good. It's just how we are. 8am to 4pm is my ideal work day.

@PaŭloEbermann No, unfortunately.

Not a full answer, but sometimes, one of our dev team has to come later than usual because we provide support to clients from other countries on a different time zone.

All dev teams in the entire country show up late to work? Anyway, it's all about expectations...some companies expect you in right on time, other let you come in late, work late, some even expect you to come in early, work late <gulp>.