https://www.phpglossary.com/what-is-usort-function-in-php-how-to-use-it/usort-output/
Output usort() function - PHP Glossary
Oct 22, 2017 - Output of usort() function example
outputusortfunctionphpglossary
https://www.codehaven.co.uk/php/php-arrays/sort-array-by-dates-usort/
Sort array by dates - usort
If you have an array of dates you wish to place in order 'usort' will work for you.
sort arrayby datesusort