Hello Gontofe, i presume you live in the UK, or Ireland, Portugal?? GMT time??
If not, find your country by Right clicking on clock, Adjust Time and date, click Time Zone, choose your Country from the drop down list, Click APPLY before exiting.
Is the country always changing after you set it?? Make sure you click APPLY when changing the country.
Also, when was the Last time you "Changed the battery" in your computer??? If over a year of so, maybe you need to change it??
Hope the above helps, GEP