For anyone wondering why it matters so much that time be precisely linked to the rotation of Earth, I'll note that time is a fundamental component of navigation. When you do celestial nav you make corrections down to the second, including accounting for the number of seconds your watch gains or loses. So it's not just about putting timestamps in a database. There's a straight line (a rhumb line? har har) from "what time is it" to "where are we" and in that context losing a second means you get a different longitude. Because time in this setting isn't really time--it's an indication of how far east or west of the prime meridian the sun is.