A system error will manifest in the clock and calendar by displaying improper times or time zones. The quick fix for any clock or calendar issue of this nature is to restore the defaults for the calendar. Even if you use a specialized calendar or clock, the whole system operates off the system clock. The easiest way to access the clock settings is to right-click the clock on the lower task bar of the main window. A pop-up menu comes up with the option "Properties." If you click "Properties" and then "Restore Defaults," the clock and calendar will revert back to factory settings. You will want to go back into the settings and adjust the time zone and personalized settings after restoring the defaults.
The visual clock runs off of the system clock. Restoring the basic defaults corrects how the operating system interprets the system clock. On bootup, your computer will display an option to access the BIOS by pressing "F8" or "DEL" on the keyboard. The BIOS represents the main controls for the system. Inside the BIOS main menu, you are presented with multiple options, including adjusting the system date and time. The operating system automatically updates to the system date and time set in the BIOS. If your system is set to a time other than your local time, your clock and calendar will revert back to this setting despite manual adjustment to the clock from your main window.
The primary cause of a calendar or clock reset is a defective onboard battery. Like most watches, computers maintain the accurate time by using a battery backup. The battery maintains power to memory modules that hold basic operating information, including the system time. After one to two years, the battery starts to fail and requires replacement. If you choose to swap out the battery yourself, you will have to open the case and look for what appears to be a watch battery or a cordless phone battery. Most computers use the watch battery. Always make sure the computer is turned off and the power cord is unplugged before attempting to access the insides of the computer.
If you are using advanced programs for calendars and times, such as Microsoft Outlook, the settings inside the program may become corrupted. Two options are available to adjust the settings within the program. A help file under the "Index" or "Help" menu will assist you to adjust the settings or restore the defaults for the program. A drastic but effective fix is to go through the "Control Panel" and "Add / Remove Software" to remove the program from the computer. Reinstalling the program after removing it corrects most common problems, such as date and time issues.