how many kiloseconds are in a day and megaseconds in a year

I hope you are joking, because this is the kind of calculations that metric makes appealing, because they are no different than how many seconds are in 3 or 24 hours. If you are not joking, then you have to rethink your education, no offense intended. Here: 246060/1000 = 86.4 ks in a day, and approximately 365.25 times this number over 1000 is 31.5576 Ms in a year. Some, you know, elementary school shit.

Seriously, one could say that, specifically regarding time, base 60 is more practical for everyday use. It is easily divisible with common fractions of time, like 1/2, 1/3, 1/4, 1/5 of 60 are all meaningful fractions of an hour (30, 20, 15).

On top of that, time is one domain of everyday life that humanity is constrained by random, global constants, like earth's rotation and the (approximately) 24-hour day cycle. Earth as part of the planetary system is not a human construct and thus it can't be made to taste, using any system. (But roads, ships, boxes, and bottles can.)

Having shortcut names for common subdivisions of anything is not an argument in itself. In fact this is a combination of fallacies. 1. Proponents of the metric system prefer its far-reaching consistency (base-10 for measuring most things, and at any scale however large or small; the original reason your argument is fallacious). Imperial has arbitrary bases for different things.

2. Citing "megaseconds" and the like is just whataboutism. There are microseconds and milliseconds in common use, as a counter, as well as hectoseconds and other divisions in use, depending on application. Your computer does not count years, days, hours or minutes, it calculates them to make its internal time representation more user friendly.

In fact, the imperial system's cultural ramifications are way more important than the choice of system. If the US wasn't deeply a backwards international pariah run by homeschooled cultist criminals with zero critical thinking skills, as demonstrated above, it would have adopted metric at least partially, like all industrialized nations. It correlates fully with its 1st and 2nd Amendment conundrums (its inability to interpret the constitution beyond face value, and thus be unable to ban hate speech and selling battlefield weaponry in grocery stores), and it comes as no surprise this fascist takeover is happening right now in the land of weekly mass shootings at schools.

It is like meeting someone for the first time and him quoting Jordan Peterson, US's imperial system fixation is a red flag for its national character in whole.