APC product warranties are based on a fixed period of time starting from the purchase date of the unit. If proof of purchase cannot be obtained, the warranty duration is calculated from the manufacture date of the unit. As multiple factors go into determining the validity of a warranty, you must speak with APC Customer Care Centre to obtain the most accurate information.
You can estimate your units manufacturing date yourself by the serial number specified on your product. The third and fourth digits indicate the year your unit was manufactured, while the following 2 characters are the week your unit was manufactured.