Got my boys to actually get along for an entire day

I have a 6 and an 8 year old who fight constantly. Over everything. Today I took them to the lake and they actually played together the whole time without one argument. Built a sand castle, went swimming, just vibed. Wife couldn't believe it when we got home. I'm not sure what I did different but I'm riding this high forever. Pretty sure that's the best parenting day I'm going to have.