Windows XP Home: 6 year old laptop, no other problems, well maintained and clean Today is Wed., Jan. 10 2012. It is 9:30PM, Eastern Time. My clock is telling me that it is Wed., Jan 11, 2012 and 9:30AM, Eastern Time. It thinks it's 12 hours earlier tomorrow! I went through the entire Adjust Date/Time. I can't put the correct date of Jan. 11 in, because that would make it Tuesday on day of the week. I can't get the PM to hold. I thought if I change the clock to the 24 hour Military Time that I might be able to resolve the problem. But going through the Control Panel> "Date, Time, Language and Regional Options" icon> clicking on the task "Change the format of numbers, dates and times" does not open the screen to select the "H" for the 24 hour clock. I've heard tales of the CMOS battery, but never had any problem. I have no idea how the time (except for the AM vs PM) and day could be correct, but both the AM or PM could be wrong and today gets tomorrow's date! Would appreciate any assistance. I've had so few system problems over the years that I have no experience in problems like this.