We all have that one friend that is late to EVERYTHING. Or maybe YOU are the late friend.
I've known plenty of people who, when we tell them what time something starts, we lie and say it's actually 20 minutes earlier than it is, because we know they'll be at least 15 minutes late. You know the type. ;)
One possible reason they're late is their internal clock just sucks.
Some people are pretty good at keeping track of time while they're doing stuff, and others just aren't. And people with Type A personalities are usually better at it than Type B's.
A study had people try to guess when one minute had passed. Type A's were pretty close . . . they averaged 58 seconds. Type B's were WAY off . . . they averaged 77 seconds.
(I'm always telling my husband that he's not so great at estimating how long it takes to do things, so it looks like I'm onto something here!)
You CAN get better at it though! One way is to guess what time it is a few times a day, and then check to see how close you are. If you keep doing it for a while, you should improve.
Now, none of this addresses ANOTHER problem of the chronically late: motivation. People who want to be on time will find a way; people who don't...well...won't. That's a whole other issue!