Change shooting time when importing

Hello.
I import RAW from Canon 400D and Canon 7D.
For example, while shooting time 18:00. After you import a media info Capture Date = 14:00 (on a computer worth time zone +4).
If I change the time zone to 0 (the default UTC), then 18:00
Other programs (COP, Photoshop, Canon Zoombrowser EX) always show the correct shooting time.
Why and how is recalculated during shooting time? This is very important for sorting.
JPG but this does not happen.
Thank you.