The idea and concept of a calendar and time, is meaningless in space. Let's think about this for a minute. Time (as far as the measurement) is based off of the Earth's rotation around it's own axis. A standard day was decided to be 24 hours. Each hour is consisted of 60 minutes, and each minute is in turn made of 60 seconds. It's further measured down further and further for scientific measurement, but that's irrelevant to this discussion. The rotation of the Earth around the Sun is then chunked up into days. As the Earth takes 365.25 days to rotate back to the same position in the orbit, we would eventually become off sync with the seasons and months. This is why Leap Year is a thing. To keep December aligned with Winter in the Northern Hemisphere, and Summer in the Southern Hemisphere. It makes sense when looking at it from that point of view. Now let's "zoom out" a little on the scale. The ISS (International Space Station) takes only 90 minutes to rotate around the earth, which means it's localized day/night is way out of sync with Earth. It's still in the same orbit around the sun (mostly), so as far as year, it takes the same amount of time (hours/minutes), but would take thousands of localized days. If we look at other planets, days are more or less hours, years are more or less days, and time takes on it's own localized meaning. If we stick to a Earth based calendar, seasons no longer sync with what's happening locally. When we eventually move to interstellar travel and spend "years" on the ships, and stations, seasons no longer matter. The day night cycle is internally regulated, and hours and minutes lose much of their meaning. Then add in the complexity of the Relativity, where as we approach the speed of light, time slows down for those on board, relative to a fixed point in space. Time no longer passes the same for the occupants of the ship, as it does on Earth. Without some sort of universal constant (of which we haven't figured out yet) there's nothing other than local time. Cheers!

image: http://theorybrandagency.com/wp-content/uploads/2015/05/Albert-Einstein-Relativity.jpg

So, it's official. I'm a citizen. It's interesting to think that one day we could be looking down at the earth from a space station. Sure there have been those before us, but to be able to truly say that we're a citizen of more than just a single terrestrial body. All of this, everything we do from now on, needs to be focused on that goal. We as a Nation, as a species, and more importantly, as individuals need to constantly be pushing, in whatever way we can towards space. This is where the future begins.