Computer clocks and Relativity

[andre kesteloot]

Gang,

An acquaintance of mine owns a laptop running Windows XP.
He lives in Maryland, hence within same time-zone as mine in Virginia.
The little icon located at bottom right of his screen indicates the 
actual real current time.

If he sends out an e-mail message, however, the msg will be dated 
differently.

A msg that I send him at 1600H is marked, when he receives it, as being 
dated earlier in time, i.e., at 15:34H, about 1/2 hour earlier than real 
time
If he writes to me at 16:00H, it will be marked on my computer as having 
been sent at 16:37H, or about 1/2 later than real time

Is this a   --so far unexplained--  effect of special relativity ?

Truly Yours,
Confused in McLean