Postscript: Time

Updates for 18.0! Many of them are minor (although incredibly useful) improvements, but there is one major change that is a bit complex that came with this new version: a new time API. The time API changes how we should handle time and gives us new very interesting mechanisms to deal with clocks drifting around through time. In this addition, I try to explain things to be as clear as possible so everyone is geared to make the best out of it.