tl;dr:“The Java And Kotlin Ecosystem team at Google has worked for several years to eliminate the sources of date / time bugs in Google’s codebase. We’ve learned a lot from this. But my goal here is not to provide a laundry list of programming practices. It’s more basic than that. I hope to provide a solid “conceptual model” for how we think about date and time concepts in the most helpful way. I’m shooting for it to be understandable, usable, and to avoid saying things that are egregiously wrong.”