Weather APP.. questions

After a long time, it appears to work on a somewhat regular basis. But… I’m guessing on a lot of it and it should have some kind of guide somewhere… Am I missing this?

1: How often is the DATE on the weather app updated? Every 2 days if I leave the board on?
2: What are the temperature gradient values? Is there a legend somewhere? Why is it not available
3: Just exactly how does the forward/backward/now buttons work? It’s not clear where I am when I click that stuff. IS there
somewhere else that there’s a guide for all of this?