If I threaten to kill him here, there would be too much evidence if I actually did it. This LJ entry

While I'm as punctual as a person can be - I feel bad if I'm less than 15 minutes early - I generally don't mind waiting at all. I've waited more than half an hour in front of the cinema for people who never turned up, and had no bad feelings for them.
One of the reasons I'm so obsessed with being on time is my family, who is *always* late. If they've left the house at the time they said they'll be somewhere, it's a good day.
I've simply accepted it as one of my weird habits, that no one shares and I really don't mind to wait.

Jens, being the number one person I need to kill because he annoys me, manages to make me mind. Probably because I hate it when others have to waste their time, no matter how much I don't mind wasting mine.
He's late to every meeting. That's ok. As soon as we're more than the required five, we start without him - helps to cut down time we have to spend in the meetings.
But if we're calling an extra meeting just because of him, change the time to accommodate him and the only thing we have to discuss is his proposal - and he arrives more than 45 minutes late, I think we're justified in our general reaction of "FUCK YOU!".