Timing is everything....

Now, it is never appropriate to show up late. However, showing up too
early can be nearly as bad. If you have a four o'clock appointment to
see somebody, and you show up at 3:42, do not assume that they are
going to be able to see you, or that they will even be in the office.
Five minutes of four is nearly four o'clock. EIGHTEEN minutes of four
is nearly 3:45.

Also, don't get snippy with me, I just work here.