As a retail business owner, I have been following the 4 5 4 calendar for a few years now. It has proven to be an efficient way to manage my inventory and sales. The 4 5 4 calendar divides the year into 52 weeks, with periods of 4 weeks, 5 weeks, and 4 weeks. This helps me align my sales and promotions with the consumer demand, resulting in better profitability.