Exchanged Jokes

There is one Very Serious Law Firm.
All staff comes to work at 6am and leaves around 11pm.
Suddenly, one guy started his day at 9am.
All the guys exchanged "looks".
And he left at 6pm.
All the guys exchanged "looks".
Next day is the same story.
And the day after is the same story.
Finally, they come to this rebel to explain the rules.
He listened, kept quiet for a while and said: "Excuse me guys, I am on vacation¦"