Convert column integer values into date expressions

To convert column integer values into date expressions in PHP, you can use the date function.

Here is an example:

<?php

$column_values = ['19700101', '19700112', '19700424', '19720302', '19740529'];

foreach ($column_values as $value) {
  $date = DateTime::createFromFormat('Ymd', $value);
  echo $date->format('Y-m-d') . "\n";
}

This will output the following:

1970-01-01
1970-01-12
1970-04-24
1972-03-02
1974-05-29

Watch a video course Learn object oriented PHP

The date function takes two arguments: a format string and a timestamp. The format string specifies how to format the date (e.g. Y-m-d for year-month-day). The timestamp is a number representing the number of seconds since January 1, 1970.

In the example above, the integer values in the $column_values array are used as timestamps, and the date function converts them into date expressions in the Y-m-d format.

Note that this will only work if the integer values are valid timestamps (i.e. they represent a date after January 1, 1970). If the values are not valid timestamps, the date function will return an empty string.