[Mindey]

Normalizing Unix seconds by the number of seconds in a day, results in Unix day, which has convenient properties, such as 5th digit after decimal point corresponding to decimal second (0.864 length of traditional second).

So, dividing UNIX_SECOND by 86400, we get a decimal Unix day.

For example, if UNIX_SECOND = 1688897360, then UNIX DAY = 19547.42315, Displaying this number with time formatting, makes it extremely easy for our time-trained eyes to interpret:

19,547 4:23:15, meaning:

19th Unix decimal year

547th day of the year (5-dmonth, 4-dweek, 7-dweekday)

4:23:15 decimal time (4-dhour, 23-dminute, 15-dsecond)