Because of that short shelf-life, the daylight-saving time (DST) changeover at 2 a.m. Sunday means that computer systems at the American Red Cross, which collects, stores and distributes much of the U.S. blood supply, must have its timestamps and other time-related programming updated without any hitches.

Any problems with the time change could affect the use of collected blood platelets, an issue that the Washington-based Red Cross has been working feverishly to prevent.

To make sure its systems work properly through the weekend and beyond, the non-profit agency has been grappling with the DST issue since late last year. It's not alone. Organizations and companies across the U.S. to prepare for the DST switch. The time change used to take place on the first weekend in April; it is starting three weeks early this year because of changes in federal law aimed at energy savings.

At the same time, vendors patches and software updates to head off potential problems.

Every time the American Red Cross gets a blood donation, it is labeled and tracked by a date-and-time stamp created when it is collected, according to the agency. That stamp is an important part of the blood management process because after blood is collected it's separated into different components for different medical needs. Red blood cells, platelets and plasma all have different shelf lives. Platelets only last five days, while red blood cells have a 42-day life span. Plasma can be frozen for up to a year. The time stamp information is critical because it tells blood banks the finite shelf life for each product, according to the agency.