On WordPress Code Reference you ar able to see code for functions, hooks, classes, and methods that are being used in the current or past versions of WordPress.
This function will allow you to display the current date that a post was written. The description of the function is provided as well as parameter, return,the source code, and more.
Parameters for the_date() Function are, $format, $before, $after, and $display. The are all default with a empty value of '' and this allows for statements to be written to check the previous and next date.
WordPress Code Reference provides a lot of helpful code that can be used when looking for information on how to use a function. You can check WordPress's newest code for each version on here to see what has changed from the last version.