If you drive in South Carolina, you probably don’t need to be told that gasoline prices, since Christmas, have climbed 35.9 cents a gallon. Even though Easter is a typical stay-at-home holiday, Easter gas prices always serve as a pre-cursor to higher prices beginning May 1. The motor club AAA Carolinas says May 1 is the national deadline for refineries to start producing less-polluting summer-blend fuel. The transition pressures prices upward because supply becomes crimped. South Carolina prices have been climbing since hitting a low of $3.07 on February 10.