strtotime - PHP code example

Using the PHP Function strtotime

Working with dates and time can be challenging for PHP developers. Luckily, the built-in strtotime function provides an effective and efficient way to parse, calculate, and convert human-readable date strings into Unix timestamps. Embracing best practices and avoiding common pitfalls, the strtotime function is a Swiss Army knife that can be used to tackle even the most complicated temporal challenges.

The strtotime() function takes a textual date string as its input and converts it into a Unix timestamp, which is an integer value representing the number of seconds elapsed since the Unix epoch (January 1, 1970). In addition to basic format conversions, the strtotime() function can handle more complex scenarios such as leap years, daylight saving time, and the system's default time zone or an explicitly specified time zone in the input string.

As a polyglot linguistic chameleon, strtotime() can understand a variety of date formats. However, as with any tool, there are limits to its power. When presented with ambiguous formats that can be interpreted in multiple ways, strtotime() may stumble like a tightrope walker on windy day.

Despite this occasional hiccup, strtotime can still be a valuable tool to have at your disposal. By leveraging the strtotime function to its full potential, you can ensure that your applications are robust and reliable. To that end, let's explore some real-world examples in which the strtotime function flexes its temporal muscles. In the process, we'll learn to avoid pitfalls and best practices to navigate the strtotime landscape with confidence.

strtotime example

function rest_parse_date( $date, $force_utc = false ) {
    if ( $force_utc ) {
        $date = preg_replace( '/[+-]\d+:?\d+$/', '+00:00', $date );
    }

    $regex = '#^\d{4}-\d{2}-\d{2}[Tt ]\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:Z|[+-]\d{2}(?::\d{2})?)?$#';

    if ( ! preg_match( $regex, $date, $matches ) ) {
        return false;
    }

    return strtotime( $date );
}

/** * Parses a 3 or 6 digit hex color (with #). * * @since 5.4.0 * * @param string $color 3 or 6 digit hex color (with #). * @return string|false */
function rest_parse_hex_color( $color ) {

$this->assertEquals(0, $cookies[0]->getExpiresTime());
        $this->assertNull($cookies[0]->getDomain());
        $this->assertEquals('/', $cookies[0]->getPath());
        $this->assertFalse($cookies[0]->isSecure());
        $this->assertFalse($cookies[0]->isHttpOnly());

        $this->assertEquals('test', $cookies[1]->getName());
        $this->assertNull($cookies[1]->getValue());

        $this->assertEquals('ABC', $cookies[2]->getName());
        $this->assertEquals('AeD', $cookies[2]->getValue());
        $this->assertEquals(strtotime('Wed, 13 Jan 2021 22:23:01 GMT'), $cookies[2]->getExpiresTime());
        $this->assertEquals('dunglas.fr', $cookies[2]->getDomain());
        $this->assertEquals('/kevin', $cookies[2]->getPath());
        $this->assertTrue($cookies[2]->isSecure());
        $this->assertTrue($cookies[2]->isHttpOnly());
        if (\defined('Symfony\Component\HttpFoundation\Cookie::SAMESITE_STRICT')) {
            $this->assertEquals(Cookie::SAMESITE_STRICT, $cookies[2]->getSameSite());
        }

        $this->assertEquals('The response body', $symfonyResponse->getContent());
        $this->assertEquals(200, $symfonyResponse->getStatusCode());

if ( in_array( 'slug', $fields, true ) ) {
            $data['slug'] = $user->user_nicename;
        }

        if ( in_array( 'roles', $fields, true ) ) {
            // Defensively call array_values() to ensure an array is returned.             $data['roles'] = array_values( $user->roles );
        }

        if ( in_array( 'registered_date', $fields, true ) ) {
            $data['registered_date'] = gmdate( 'c', strtotime( $user->user_registered ) );
        }

        if ( in_array( 'capabilities', $fields, true ) ) {
            $data['capabilities'] = (object) $user->allcaps;
        }

        if ( in_array( 'extra_capabilities', $fields, true ) ) {
            $data['extra_capabilities'] = (object) $user->caps;
        }

        if ( in_array( 'avatar_urls', $fields, true ) ) {

continue;
            }

            if (null !== $requestBody && $requestBody !== $this->getContent($request['postData'] ?? [])) {
                continue;
            }

            $info = [
                'http_code' => $response['status'],
                'http_method' => $entryMethod,
                'response_headers' => [],
                'start_time' => strtotime($startedDateTime),
                'url' => $entryUrl,
            ];

            /** @var array{name: string, value: string} $header */
            foreach ($response['headers'] as $header) {
                ['name' => $name, 'value' => $value] = $header;

                $info['response_headers'][$name][] = $value;
            }

            return new MockResponse($body, $info);
        }

        $data = $this->get('db')->fetchAll($sql, [$timeBack]);

        $result = [];
        foreach ($data as $row) {
            $result[] = [
                'timestamp' => strtotime($row['date']),
                'date' => date('d.m.Y', strtotime($row['date'])),
                'visitors' => $row['visitors'],
            ];
        }

        // Get current users online         $currentUsers = $this->get('db')->fetchOne(
            'SELECT COUNT(DISTINCT remoteaddr) FROM s_statistics_currentusers WHERE time > DATE_SUB(NOW(), INTERVAL 3 MINUTE)'
        );

/** * Checks if a date string is plausible. * If not, returns null. Otherwise the string. * * @param string $date * * @return string|null */
    private function checkDate($date)
    {
        $dateCheck = strtotime($date);

        return \is_int($dateCheck) && $dateCheck > 0 ? $date : null;
    }
}

elseif ($string instanceof DateTime) {
        return $string->getTimestamp();
    } elseif (strlen($string) == 14 && ctype_digit($string)) {
        // it is mysql timestamp format of YYYYMMDDHHMMSS?         return mktime(substr($string, 8, 2),substr($string, 10, 2),substr($string, 12, 2),
                       substr($string, 4, 2),substr($string, 6, 2),substr($string, 0, 4));
    } elseif (is_numeric($string)) {
        // it is a numeric string, we handle it as timestamp         return (int) $string;
    } else {
        // strtotime should handle it         $time = strtotime($string);
        if ($time == -1 || $time === false) {
            // strtotime() was not able to parse $string, use "now":             return time();
        }
        return $time;
    }
}

?>

$summary = parent::settingsSummary();

    $time_diff = $this->getSetting('time_diff');
    $date_format = $this->getSetting('date_format');
    $date_format = $date_format === static::CUSTOM_DATE_FORMAT ? $this->getSetting('custom_date_format') : $date_format;

    if ($time_diff['enabled']) {
      $summary[] = $this->t('Displayed as a time difference');

      $options = ['granularity' => $time_diff['granularity']];

      $timestamp = strtotime('1 year 1 month 1 week 1 day 1 hour 1 minute');
      $interval = $this->dateFormatter->formatTimeDiffUntil($timestamp, $options);
      $display = new FormattableMarkup($time_diff['future_format'], ['@interval' => $interval]);
      $summary[] = $this->t('Future date: %display', ['%display' => $display]);

      $timestamp = strtotime('-1 year -1 month -1 week -1 day -1 hour -1 minute');
      $interval = $this->dateFormatter->formatTimeDiffSince($timestamp, $options);
      $display = new FormattableMarkup($time_diff['past_format'], ['@interval' => $interval]);
      $summary[] = $this->t('Past date: %display', ['%display' => $display]);

      if ($time_diff['refresh']) {
        $refresh_intervals = $this->getRefreshIntervals();

if ( preg_match( '/([0-9]{2}):([0-9]{2})/', $lucifer[7], $l2 ) ) {
                        $b['year']   = gmdate( 'Y' );
                        $b['hour']   = $l2[1];
                        $b['minute'] = $l2[2];
                    } else {
                        $b['year']   = $lucifer[7];
                        $b['hour']   = 0;
                        $b['minute'] = 0;
                    }

                    $b['time'] = strtotime( sprintf( '%d %s %d %02d:%02d', $b['day'], $b['month'], $b['year'], $b['hour'], $b['minute'] ) );
                    $b['name'] = $lucifer[8];
                }
            }
        }

        // Replace symlinks formatted as "source -> target" with just the source name.         if ( isset( $b['islink'] ) && $b['islink'] ) {
            $b['name'] = preg_replace( '/(\s*->\s*.*)$/', '', $b['name'] );
        }

        return $b;
    }

$changeset_date = wp_unslash( $_POST['customize_changeset_date'] );
            if ( preg_match( '/^\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d$/', $changeset_date ) ) {
                $mm         = substr( $changeset_date, 5, 2 );
                $jj         = substr( $changeset_date, 8, 2 );
                $aa         = substr( $changeset_date, 0, 4 );
                $valid_date = wp_checkdate( $mm, $jj, $aa, $changeset_date );
                if ( ! $valid_date ) {
                    wp_send_json_error( 'bad_customize_changeset_date', 400 );
                }
                $changeset_date_gmt = get_gmt_from_date( $changeset_date );
            } else {
                $timestamp = strtotime( $changeset_date );
                if ( ! $timestamp ) {
                    wp_send_json_error( 'bad_customize_changeset_date', 400 );
                }
                $changeset_date_gmt = gmdate( 'Y-m-d H:i:s', $timestamp );
            }
        }

        $lock_user_id = null;
        $autosave     = ! empty( $_POST['customize_changeset_autosave'] );
        if ( ! $is_new_changeset ) {
            $lock_user_id = wp_check_post_lock( $this->changeset_post_id() );
        }

namespace Symfony\Component\BrowserKit\Tests;

use PHPUnit\Framework\TestCase;
use Symfony\Component\BrowserKit\Cookie;
use Symfony\Component\BrowserKit\Exception\InvalidArgumentException;
use Symfony\Component\BrowserKit\Exception\UnexpectedValueException;

class CookieTest extends TestCase
{
    public function testToString()
    {
        $cookie = new Cookie('foo', 'bar', strtotime('Fri, 20-May-2011 15:25:52 GMT'), '/', '.myfoodomain.com', true);
        $this->assertEquals('foo=bar; expires=Fri, 20 May 2011 15:25:52 GMT; domain=.myfoodomain.com; path=/; secure; httponly', (string) $cookie, '->__toString() returns string representation of the cookie');

        $cookie = new Cookie('foo', 'bar with white spaces', strtotime('Fri, 20-May-2011 15:25:52 GMT'), '/', '.myfoodomain.com', true);
        $this->assertEquals('foo=bar%20with%20white%20spaces; expires=Fri, 20 May 2011 15:25:52 GMT; domain=.myfoodomain.com; path=/; secure; httponly', (string) $cookie, '->__toString() encodes the value of the cookie according to RFC 3986 (white space = %20)');

        $cookie = new Cookie('foo', null, 1, '/admin/', '.myfoodomain.com');
        $this->assertEquals('foo=; expires=Thu, 01 Jan 1970 00:00:01 GMT; domain=.myfoodomain.com; path=/admin/; httponly', (string) $cookie, '->__toString() returns string representation of a cleared cookie if value is NULL');

        $cookie = new Cookie('foo', 'bar', 0, '/', '');
        $this->assertEquals('foo=bar; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/; httponly', (string) $cookie);

$this->assertTrue($c->test($m), '->test() tests a string against the expression');
        }

        foreach ($noMatch as $m) {
            $this->assertFalse($c->test($m), '->test() tests a string against the expression');
        }
    }

    public static function getTestData()
    {
        return [
            ['< 2005-10-10', [strtotime('2005-10-09')], [strtotime('2005-10-15')]],
            ['until 2005-10-10', [strtotime('2005-10-09')], [strtotime('2005-10-15')]],
            ['before 2005-10-10', [strtotime('2005-10-09')], [strtotime('2005-10-15')]],
            ['> 2005-10-10', [strtotime('2005-10-15')], [strtotime('2005-10-09')]],
            ['after 2005-10-10', [strtotime('2005-10-15')], [strtotime('2005-10-09')]],
            ['since 2005-10-10', [strtotime('2005-10-15')], [strtotime('2005-10-09')]],
            ['!= 2005-10-10', [strtotime('2005-10-11')], [strtotime('2005-10-10')]],
        ];
    }
}

CriteriaPartInterface $criteriaPart,
        Criteria $criteria,
        Search $search,
        ShopContextInterface $context
    ) {
        $search->addPostFilter($this->getQuery());
    }

    private function getQuery(): RangeQuery
    {
        $dayLimit = (int) $this->config->get('markAsNew');
        $timestamp = strtotime('-' . $dayLimit . ' days');
        if ($timestamp === false) {
            throw new RuntimeException(sprintf('Could not convert "-%s days" into a timestamp', $dayLimit));
        }

        return new RangeQuery('formattedCreatedAt', [
            'gte' => date('Y-m-d', $timestamp),
            'lte' => date('Y-m-d'),
        ]);
    }
}

        /** @var Enlight_Controller_Front $controller */
        $controller = $this->container->get('front');

        if ($this->container->initialized('session')) {
            $session = $this->container->get('session');
            $session->offsetSet('auto-user', null);
        }

        $controller->Response()->headers->setCookie(
            new Cookie('slt', null, strtotime('-1 Year'), $controller->Request()->getBasePath() . '/')
        );
    }

    public function checkCookie(Enlight_Controller_EventArgs $args)
    {
        $request = $args->getRequest();

        $config = $this->container->get(Shopware_Components_Config::class);

        if (!$config->get('useSltCookie')) {
            return;
        }

static::assertMatchesRegularExpression('/\/\/ No expired files found./', $message);
    }

    public function testExecuteWithAllFilesExpired(): void
    {
        $num = 5;
        $data = $this->prepareImportExportFileTestData($num);

        $filePathes = [];
        foreach (array_keys($data) as $key) {
            $filePathes[] = $data[$key]['path'];
            $data[$key]['expireDate'] = date('Y-m-d H:i:s', strtotime('-1 second'));
        }

        $this->fileRepository->create(array_values($data), $this->context);

        $commandTester = new CommandTester($this->deleteExpiredFilesCommand);
        $commandTester->setInputs(['y']);
        $commandTester->execute([]);

        $message = $commandTester->getDisplay();
        static::assertMatchesRegularExpression(
            sprintf('/Are you sure that you want to delete %d expired files\? $yes\/no$ \[no\]:/', $num),