Importance of Correct Computer Date & Time

Keeping the correct time on your computer is essential, especially if you're using it as a business machine. The computer keeps its own date and time internally and uses it on files, documents, and reminders. If you set the clock incorrectly, bad dates become a flood of erroneous information, leading to lost files, missed appointments and poor recordkeeping.

All PCs have an electronic circuit called a "real-time clock" that keeps track of the date and time. The circuit gets its power from a battery, so when you shut the computer off the clock continues to keep accurate time. The Windows operating system reads the clock's data whenever it needs the current date or time. Although the computer manufacturer sets the clock at the factory, you usually need to set it again to your local time zone. Once it's set correctly, you rarely need to set it again.

Whenever your computer creates a new file or modifies an existing one, it stamps the file with the current date and time. This information allows the computer to organize files chronologically. An incorrect clock renders these dates unreliable, making it harder to find files when you need them. Microsoft Word and other programs use the current date and time in document status information, headings and other features, but the date comes from the internal clock. A bad date on correspondence can lead to misunderstandings and legal complications.

Personal information managers such as Outlook rely on the computer's internal clock to keep accurate dates and times. Outlook also uses the clock to trigger appointment reminders. If the clock is set incorrectly, Outlook's reminders will go off at the wrong time, potentially throwing your schedule into chaos.

Database management software "stamps" the date and time onto data records using the clock data. Databases typically determine information such as billing and shipping dates automatically from the clock date. A minor mistake such as the current date being off by one month can spell serious trouble for your business, suppliers and customers.

Inaccurate dates can also cause problems with your computer's security software. For example, when you visit an online retailer, your browser program checks the site's security certificate file. The file contains a date code used to verify the site's legitimacy, but an error in the clock may flag the certificate as expired or not yet valid. Other programs affected by bad dates include anti-virus software such as Microsoft Security Essentials. The software may crash if the clock has an incorrect setting.