I agree that calendar reform is futile, it&#x27;s more useful to have a universal standard than trying to get everyone to agree on a marginally better one. But it&#x27;s fun to think about how you could design the calendar from scratch, or how we should do it on Mars.<p>Besides social inertia, I have not heard a good argument for lunar months. I convert months to day numbers (feb 29 becomes day 60) in my head, which makes reasoning about longer time scales a little easier.