It’s one of those neat but pointless observations. A “day” is one rotation of a planet on its axis. That rotation on earth is not a constant 24 hours. For making things simple and standard we decide to call 24 hours a day, and 365 days a year even though those times do not match up to the movement of the Earth. So leap years and the like are used to fudge the unaccounted time. That’s using a standard solar calendar though. If you use a lunar or other calendar this doesn’t apply. It’s arbitrary. If you want to define a day as a picosecond then every day of your life will effectively be the same length. But beyond semantics- few people I know measure life in hours. Years is more common, but really life is measured in moments. The length of a moment is inconsistent and irrelevant. Moments make memories, you likely don’t remeber every hour of your life, but there are probably seconds that for better or for worse you’d never forget.
Except for twice
One Begins and one's Goodbye
Edit: on the gram.