Php use server time

date

Returns a string formatted according to the given format string using the given integer timestamp (Unix timestamp) or the current time if no timestamp is given. In other words, timestamp is optional and defaults to the value of time() .

Unix timestamps do not handle timezones. Use the DateTimeImmutable class, and its DateTimeInterface::format() formatting method to format date/time information with a timezone attached.

Parameters

Note: date() will always generate 000000 as microseconds since it takes an int parameter, whereas DateTime::format() does support microseconds if DateTime was created with microseconds.

The optional timestamp parameter is an int Unix timestamp that defaults to the current local time if timestamp is omitted or null . In other words, it defaults to the value of time() .

Return Values

Returns a formatted date string.

Errors/Exceptions

Every call to a date/time function will generate a E_WARNING if the time zone is not valid. See also date_default_timezone_set()

Changelog

Version	Description
8.0.0	timestamp is nullable now.

Examples

Example #1 date() examples

// set the default timezone to use.
date_default_timezone_set ( ‘UTC’ );

// Prints something like: Monday
echo date ( «l» );

// Prints something like: Monday 8th of August 2005 03:12:46 PM
echo date ( ‘l jS \of F Y h:i:s A’ );

// Prints: July 1, 2000 is on a Saturday
echo «July 1, 2000 is on a » . date ( «l» , mktime ( 0 , 0 , 0 , 7 , 1 , 2000 ));

/* use the constants in the format parameter */
// prints something like: Wed, 25 Sep 2013 15:28:57 -0700
echo date ( DATE_RFC2822 );

// prints something like: 2000-07-01T00:00:00+00:00
echo date ( DATE_ATOM , mktime ( 0 , 0 , 0 , 7 , 1 , 2000 ));
?>

You can prevent a recognized character in the format string from being expanded by escaping it with a preceding backslash. If the character with a backslash is already a special sequence, you may need to also escape the backslash.

Example #2 Escaping characters in date()

It is possible to use date() and mktime() together to find dates in the future or the past.

Example #3 date() and mktime() example

$tomorrow = mktime ( 0 , 0 , 0 , date ( «m» ) , date ( «d» )+ 1 , date ( «Y» ));
$lastmonth = mktime ( 0 , 0 , 0 , date ( «m» )- 1 , date ( «d» ), date ( «Y» ));
$nextyear = mktime ( 0 , 0 , 0 , date ( «m» ), date ( «d» ), date ( «Y» )+ 1 );
?>

Note:

This can be more reliable than simply adding or subtracting the number of seconds in a day or month to a timestamp because of daylight saving time.

Some examples of date() formatting. Note that you should escape any other characters, as any which currently have a special meaning will produce undesirable results, and other characters may be assigned meaning in future PHP versions. When escaping, be sure to use single quotes to prevent characters like \n from becoming newlines.

Example #4 date() Formatting

// Assuming today is March 10th, 2001, 5:16:18 pm, and that we are in the
// Mountain Standard Time (MST) Time Zone

$today = date ( «F j, Y, g:i a» ); // March 10, 2001, 5:16 pm
$today = date ( «m.d.y» ); // 03.10.01
$today = date ( «j, n, Y» ); // 10, 3, 2001
$today = date ( «Ymd» ); // 20010310
$today = date ( ‘h-i-s, j-m-y, it is w Day’ ); // 05-16-18, 10-03-01, 1631 1618 6 Satpm01
$today = date ( ‘\i\t \i\s \t\h\e jS \d\a\y.’ ); // it is the 10th day.
$today = date ( «D M j G:i:s T Y» ); // Sat Mar 10 17:16:18 MST 2001
$today = date ( ‘H:m:s \m \i\s\ \m\o\n\t\h’ ); // 17:03:18 m is month
$today = date ( «H:i:s» ); // 17:16:18
$today = date ( «Y-m-d H:i:s» ); // 2001-03-10 17:16:18 (the MySQL DATETIME format)
?>

To format dates in other languages, IntlDateFormatter::format() can be used instead of date() .

Notes

Note:

To generate a timestamp from a string representation of the date, you may be able to use strtotime() . Additionally, some databases have functions to convert their date formats into timestamps (such as MySQL’s » UNIX_TIMESTAMP function).

Timestamp of the start of the request is available in $_SERVER[‘REQUEST_TIME’] .

See Also

• DateTimeImmutable::__construct() — Returns new DateTimeImmutable object
• DateTimeInterface::format() — Returns date formatted according to given format
• gmdate() — Format a GMT/UTC date/time
• idate() — Format a local time/date part as integer
• getdate() — Get date/time information
• getlastmod() — Gets time of last page modification
• mktime() — Get Unix timestamp for a date
• IntlDateFormatter::format() — Format the date/time value as a string
• time() — Return current Unix timestamp
• Predefined DateTime Constants

User Contributed Notes

• Date/Time Functions
  • checkdate
  • date_​add
  • date_​create_​from_​format
  • date_​create_​immutable_​from_​format
  • date_​create_​immutable
  • date_​create
  • date_​date_​set
  • date_​default_​timezone_​get
  • date_​default_​timezone_​set
  • date_​diff
  • date_​format
  • date_​get_​last_​errors
  • date_​interval_​create_​from_​date_​string
  • date_​interval_​format
  • date_​isodate_​set
  • date_​modify
  • date_​offset_​get
  • date_​parse_​from_​format
  • date_​parse
  • date_​sub
  • date_​sun_​info
  • date_​sunrise
  • date_​sunset
  • date_​time_​set
  • date_​timestamp_​get
  • date_​timestamp_​set
  • date_​timezone_​get
  • date_​timezone_​set
  • date
  • getdate
  • gettimeofday
  • gmdate
  • gmmktime
  • gmstrftime
  • idate
  • localtime
  • microtime
  • mktime
  • strftime
  • strptime
  • strtotime
  • time
  • timezone_​abbreviations_​list
  • timezone_​identifiers_​list
  • timezone_​location_​get
  • timezone_​name_​from_​abbr
  • timezone_​name_​get
  • timezone_​offset_​get
  • timezone_​open
  • timezone_​transitions_​get
  • timezone_​version_​get

  Источник

  PHP Date and Time

  The PHP date() function is used to format a date and/or a time.

  The PHP Date() Function

  The PHP date() function formats a timestamp to a more readable date and time.

  Syntax

  Parameter	Description
  format	Required. Specifies the format of the timestamp
  timestamp	Optional. Specifies a timestamp. Default is the current date and time

  A timestamp is a sequence of characters, denoting the date and/or time at which a certain event occurred.

  Get a Date

  The required format parameter of the date() function specifies how to format the date (or time).

  Here are some characters that are commonly used for dates:

  • d — Represents the day of the month (01 to 31)
  • m — Represents a month (01 to 12)
  • Y — Represents a year (in four digits)
  • l (lowercase ‘L’) — Represents the day of the week

  Other characters, like»/», «.», or «-» can also be inserted between the characters to add additional formatting.

  The example below formats today’s date in three different ways:

  Example

  echo «Today is » . date(«Y/m/d») . «
  «;
  echo «Today is » . date(«Y.m.d») . «
  «;
  echo «Today is » . date(«Y-m-d») . «
  «;
  echo «Today is » . date(«l»);
  ?>

  PHP Tip — Automatic Copyright Year

  Use the date() function to automatically update the copyright year on your website:

  Example

  Get a Time

  Here are some characters that are commonly used for times:

  • H — 24-hour format of an hour (00 to 23)
  • h — 12-hour format of an hour with leading zeros (01 to 12)
  • i — Minutes with leading zeros (00 to 59)
  • s — Seconds with leading zeros (00 to 59)
  • a — Lowercase Ante meridiem and Post meridiem (am or pm)

  The example below outputs the current time in the specified format:

  Example

  Note that the PHP date() function will return the current date/time of the server!

  Get Your Time Zone

  If the time you got back from the code is not correct, it’s probably because your server is in another country or set up for a different timezone.

  So, if you need the time to be correct according to a specific location, you can set the timezone you want to use.

  The example below sets the timezone to «America/New_York», then outputs the current time in the specified format:

  Example

  Create a Date With mktime()

  The optional timestamp parameter in the date() function specifies a timestamp. If omitted, the current date and time will be used (as in the examples above).

  The PHP mktime() function returns the Unix timestamp for a date. The Unix timestamp contains the number of seconds between the Unix Epoch (January 1 1970 00:00:00 GMT) and the time specified.

  Syntax

  The example below creates a date and time with the date() function from a number of parameters in the mktime() function:

  Example

  Create a Date From a String With strtotime()

  The PHP strtotime() function is used to convert a human readable date string into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 GMT).

  Syntax

  The example below creates a date and time from the strtotime() function:

  Example

  PHP is quite clever about converting a string to a date, so you can put in various values:

  Example

  $d=strtotime(«next Saturday»);
  echo date(«Y-m-d h:i:sa», $d) . «
  «;

  However, strtotime() is not perfect, so remember to check the strings you put in there.

  More Date Examples

  The example below outputs the dates for the next six Saturdays:

  Example

  $startdate = strtotime(«Saturday»);
  $enddate = strtotime(«+6 weeks», $startdate);

  while ($startdate < $enddate) echo date("M d", $startdate) . "
  «;
  $startdate = strtotime(«+1 week», $startdate);
  >
  ?>

  The example below outputs the number of days until 4th of July:

  Example

  $d1=strtotime(«July 04»);
  $d2=ceil(($d1-time())/60/60/24);
  echo «There are » . $d2 .» days until 4th of July.»;
  ?>

  Complete PHP Date Reference

  For a complete reference of all date functions, go to our complete PHP Date Reference.

  The reference contains a brief description, and examples of use, for each function!

  Источник

  Синхронизация времени с NTP — сервером на PHP (по протоколу DAYTIME)

  Одним из первых протоколов точного времени, используемым на компьютерах, был DAYTIME (RFC 867), предназначенный для сообщения даты и времени в понятном человеку виде. Формат ответа DAYTIME строго не регламентируется и не предназначен для машинной обработки — предполагается лишь, что человеку, прочитавшему полученную строку, станет ясно текущее время.

  Реализуем простую функцию для получения точного времени:

  function queryTimeServer ($timeserver, $socket) < $timevalue = 0; $ret = array(); $fp = @fsockopen($timeserver,$socket,$err,$errstr,5); if ($fp) < fputs($fp,"\n"); $timevalue = fread($fp,49); fclose($fp); >$ret['time'] = $timevalue; $ret['errno'] = $err; $ret['errstr'] = $errstr; return $ret; >

  // По умолчанию берем время с нашего сервера $timevalue = time(); // Если запрос к NTP успешен - берем время из него $timercvd = queryTimeServer("pool.ntp.org", 13); if (!$timercvd['errno'] && $timercvd['time'] > 0) < $timevalue = strtotime($timercvd[0]); >echo "
  Точное время: ";

  Для получения точного времени помимо pool.ntp.org также можно использовать следующие сервера:

  • time.windows.com
  • time.nist.gov
  • time-a.nist.gov
  • time-b.nist.gov
  • time-a.timefreq.bldrdoc.gov
  • time-b.timefreq.bldrdoc.gov
  • time-c.timefreq.bldrdoc.gov

  Не следует путать daytime protocol RFC 867 с NTP или time protocol RFC 868

  Ссылки

  Источник

  Live Server Time Clock using PHP and Javascript

  Posted 4:08 pm by muni & filed under JAVASCRIPT, JQUERY, PHP.

  In this tutorial we are going to see how to set up PHP timestamp in javascript date object to simulate real time clock.
  If we are going to make clock script only in php, for every second we need to make an ajax call to the server to get sever time to display on clicent side. It is completely bad scripting for making ajax call for every second to the server.
  It good idea to assign php timestamp (server in time) to javascript variable, and run a javscript clock from that timestamp gives exact server time on the client side without making ajax call to the server.

  

  Live Server Time Clock Using PHP Javascript

  Create index.php file. Now get php timestamp from php inbuilt DateTime class.

  Now $current_timestamp will have current time in seconds from ( Jan 1, 1970). That’s it on PHP side.

  where Javascript setInterval() method calls the phpJavascriptClock() function for every second to simulate real time clock.

  flag variable helps to assign php timestamp to javscript timer variable only on page load.

  But on subseqent function call ( phpJavascriptClock() ) value in the timer variable will incremented with 1000.

  Here is the full Javascript clock script.

   flag = true; timer = ''; setInterval(function(),1000); function phpJavascriptClock() < if ( flag ) < timer = *1000; > var d = new Date(timer); months = new Array('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sept', 'Oct', 'Nov', 'Dec'); month_array = new Array('January', 'Febuary', 'March', 'April', 'May', 'June', 'July', 'Augest', 'September', 'October', 'November', 'December'); currentYear = d.getFullYear(); month = d.getMonth(); var currentMonth = months[month]; var currentMonth1 = month_array[month]; var currentDate = d.getDate(); currentDate = currentDate < 10 ? '0'+currentDate : currentDate; var hours = d.getHours(); var minutes = d.getMinutes(); var seconds = d.getSeconds(); var ampm = hours >= 12 ? 'PM' : 'AM'; hours = hours % 12; hours = hours ? hours : 12; // the hour ’0' should be ’12' minutes = minutes

  Источник