This varies from individual to individual and from organization to organization. I had set a norm that by the first siren of the factory (6.45 am and the shift starts at 7.00 am) to be inside the factory premises. Unless the boss sets an example, he has no right to expect compliance from others. There has been earlier discussion on this topic, of sales and marketing people being exceptions to the general rule. There could be many reasons. Indeed, most middle-level and senior executives work very late into the evenings, which is the justification claimed for coming late. In Marketing/Sales, the most often heard alibi is that there won't be customers available early in the morning but they would be at work near the close of the shift hours. There are too many well-known business heads who have made a personal habit of arriving before time (like JRD Tata, E. Sridharan, V. Krishnamurthy, Amul Kurien, etc.). These days, there are flexitime, work from home, etc. Rigidity regarding timeliness and punctuality has to be strictly viewed from the organizational perspective. But let us not forget the age-old adage that timeliness is next to godliness.