It's that time of year when people are busy cooking, shopping and spending time with family. Giving blood is not high on the to-do list.

Dick Miller, director of donor recruitment for the South Carolina region of the American Red Cross, said that although the supply looks fine, the critical time of the year is around the corner.

The regional supply is at three days, the minimum safe level, Miller said.

"The challenge we're faced with is the next four days and people not coming in," he said.

After Thanksgiving, blood collectors must go into high gear to stock up for the toughest sustained period of the year: mid-December to mid-January.

Other reasons for the slowdown are people taking time off work and not being in their routines. Also, flu season sets in.

The days before a holiday can strain blood stores, said Michelle Yacob, blood bank supervisor for Trident Health System.

Blood has a shelf life of 42 days, Miller said. And platelets, which are often used for cancer patients, last only five days.