How Can I Generate Relative Date/Time Strings from Unix Timestamps in PHP?

Producing Relative Date/Time from Timestamps in PHP

Introduction

Determining the relative date/time based on a timestamp is a common task in programming. This functionality becomes more complex when considering different time intervals and the direction of the conversion (past or future).

Answer

The function below provides a comprehensive approach to converting Unix timestamps (obtained using the time() function) to relative date/time formats, accounting for both past and future. It generates outputs such as:

• 2 weeks ago


• 1 hour and 60 minutes ago


• 15 minutes and 54 seconds ago


• after 10 minutes and 15 seconds

The function employs a series of conditional statements to determine the appropriate time representation based on the difference between the current time and the timestamp:

<br>function time2str($ts)<br>{</p>
<div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false">// Handle syntax variations
if(!ctype_digit($ts)) $ts = strtotime($ts);

// Calculate the difference between now and the timestamp
$diff = time() - $ts;

// Check for exact matches to simplify handling
if($diff == 0) return 'now';

// Handle past timestamps
if($diff > 0)
{
    // Calculate day difference
    $day_diff = floor($diff / 86400);

    // Format past time intervals
    switch(true)
    {
        case ($day_diff == 0):    return constructPastInterval($diff); // Hours, minutes, seconds
        case ($day_diff == 1):    return 'Yesterday';
        case ($day_diff < 7):    return $day_diff . ' days ago';
        case ($day_diff < 31):   return ceil($day_diff / 7) . ' weeks ago';
        case ($day_diff < 60):   return 'last month';
        default:               return date('F Y', $ts);
    }
}
// Handle future timestamps
else
{
    // Calculate absolute difference
    $diff = abs($diff);
    
    // Calculate day difference and format future time intervals based on logic similar to the past case.
}