So if I always arrive 10 minutes before end of work I still put have constraints on myself or have constraints in terms of work hours ? True. Sophist Reasoning but true.

@ThePassenger This sounds like a fundamental misunderstanding. You never said when your teams leave the office. I assumed that "regular" teams work 8hrs since 10 and "dev team" works 8 hours since 12. It's not possible to "arrive 10 minutes before end of work", because by law you always arrive 8 hrs before end of your work. If devs work only 6hrs, then ask a question "why they work 2 hrs less".

Yes, I don't have this information. So I can't conclude to your conclusions.

@ThePassenger So, what are you asking then? What do you mean by "constraint"? For me, "constraint" is the time window when I can adjust starting of my workday freely. So, if I must arrive between 11:30 and 12:00, that's 30m constraint. If I must arrive between 8:00 and 10:00 that's 2 hour constraint. Whatever the time I make it, I sit 8hours.

The unspoken rule is here, but I think most businesses looks more or less the same, is that everybody arrives between 9:30 and 10:00 Yet, the dev team (front/back) always arrives between 11:30 and 12pm. Therfore they seem to be less constrained or have less constraints. To what extent dev have less time constraints is my question.

@ThePassenger There is no such rule. Just because one team has their workshift offset 2 hours proves that your rule is not there. They don't appear to be less constrained, because it seems they can't come before 11. Eg in my office the rule is that we arrive between 8 and 9. But that's not unspoken, that's official. And I have a smaller constraint than you, 60 minutes instead of 30. Every business have it differently: at the supermarket near my place employees arrive at 5:30 because it opens at 6:00.

I think there is, I didn't mentioned workshift but the fact that everybody arrives at 9:30-10 but the dev. The fact they arrive later can also prove they violate it. It's not because I don't respect the rule that it doesn't exist as it's not because I rape someone that article 222-23 forbiding rapes of Penal Code doesn't exist. Some rule are said and written, other are social and unspoken like putting your finger in your ass before shaking hands. Anyway, this is turning opinion-based.

The only opinion here is yours, that everybody should arrive at 9

there is no such rule, look around and see that most business don't start at 9. Some start at 5, others at 10

The unspoken rule in this case study is to arrive from 9h30 to 10. Your opinion here is that unspoken rules that comes from interpersonal and social skills doesn't exist. Which I deny with the simple example of finger ass shaking hands

I have literally written in my contract that I can't arrive after 9

Are you saying that your unspoken rule is more important than my contract?

If they are conflicting ?

you said 9:30-10 and my contract says 8:00-9:00. That is a conflict

Depends on your case. Here they are paid by day of work. But it tends to be mid-day paid a day

If on your case contracts ask you to arrive at 8-9 and everybody sticks to it the social rule is in adequation with the written one and I see no issue.

Let's assume everbody is paid by 8 hrs of work per day

I say: what you perceive as an unspoken social rule is merely a coincidence. Most people are needed between 10:00 and 17:00, because they interact with another businesses that work similar hours

So they arrive at 9:30

devs do not interact with other businesses at all

and only very little with other teams

they are not needed all 7 hours

so, in this case it doesn't matter if they arrive at 9 or at 12

all that it matters is that all team arrives at once