Bill Gates on what Warren Buffett's calendar taught him about time:Bill Gates built his career packing every minute.As he recalls it: "I had every minute packed and I thought that was the only way you could do things." Then Buffett showed him his calendar, and it changed how Gates thought about time entirely.Buffett's calendar looked nothing like that.Whole days sat blank.Flipping through it, Gates notes: "he has days that there's nothing on." One stretch was almost comically empty. As Gates des