A PHP function to display the time between now and a future date supplied as Unix time, in human readable format, using two blocks of time periods (year, month, week, day, hour or minute.)

function TimeTo($future) // $original should be the future date and time in unix format
{
    // Common time periods as an array of arrays
    $periods = array(
        array(60 * 60 * 24 * 365 , 'year'),
        array(60 * 60 * 24 * 30 , 'month'),
        array(60 * 60 * 24 * 7, 'week'),
        array(60 * 60 * 24 , 'day'),
        array(60 * 60 , 'hour'),
        array(60 , 'minute'),
    );
   
    $today = time();
    $since = $future - $today; // Find the difference of time between now and the future
   
    // Loop around the periods, starting with the biggest
    for ($i = 0, $j = count($periods); $i < $j; $i++)
        {
        $seconds = $periods[$i][0];
        $name = $periods[$i][1];
       
        // Find the biggest whole period
        if (($count = floor($since / $seconds)) != 0)
                {
            break;
        }
    }
   
    $print = ($count == 1) ? '1 '.$name : "$count {$name}s";
   
    if ($i + 1 < $j)
        {
        // Retrieving the second relevant period
        $seconds2 = $periods[$i + 1][0];
        $name2 = $periods[$i + 1][1];
       
        // Only show it if it's greater than 0
        if (($count2 = floor(($since - ($seconds * $count)) / $seconds2)) != 0)
                {
            $print .= ($count2 == 1) ? ', 1 '.$name2 : ", $count2 {$name2}s";
        }
    }
    return $print;
}
 
echo TimeTo(1359101056);

The provided PHP function, TimeTo, calculates the time remaining until a specified future date and time, given in Unix timestamp format. Here’s a breakdown of its functionality:

1. Function Definition: function TimeTo($future) takes $future, a Unix timestamp representing a future date and time.
2. Time Periods Array: The $periods array contains common time units (year, month, week, day, hour, minute) in seconds.
3. Calculating Time Difference: The function calculates the time difference $since between the current time ($today = time();) and the future time ($future).
4. Finding the Largest Applicable Time Unit: The function loops through $periods to find the largest time unit that can be used to express the time until $future. It breaks out of the loop once it finds this unit.
5. Formatting the Output: The $print variable is set to a string representing the time in the largest unit found, in singular or plural form based on the count.
6. Adding a Second Time Period: If applicable, the function adds a second, smaller time unit to provide a more precise time description.
7. Returning the Result: The function returns the formatted string $print, indicating the time remaining until the future date.
8. Example Usage: echo TimeTo(1359101056); prints the time remaining until the Unix timestamp 1359101056.

This function is useful for displaying countdowns or time until future events in a human-readable format.