Php date year ago

Содержание

date
Parameters
Return Values
Errors/Exceptions
Changelog
Examples
Notes
See Also
User Contributed Notes 21 notes

date

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

Parameters

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. If a non-numeric value is used for timestamp , false is returned and an E_WARNING level error is emitted.

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’] .

User Contributed Notes 21 notes

Things to be aware of when using week numbers with years.

echo date ( «YW» , strtotime ( «2011-01-07» )); // gives 201101
echo date ( «YW» , strtotime ( «2011-12-31» )); // gives 201152
echo date ( «YW» , strtotime ( «2011-01-01» )); // gives 201152 too
?>

BUT

echo date ( «oW» , strtotime ( «2011-01-07» )); // gives 201101
echo date ( «oW» , strtotime ( «2011-12-31» )); // gives 201152
echo date ( «oW» , strtotime ( «2011-01-01» )); // gives 201052 (Year is different than previous example)
?>

Reason:
Y is year from the date
o is ISO-8601 year number
W is ISO-8601 week number of year

Conclusion:
if using ‘W’ for the week number use ‘o’ for the year.

If you have a problem with the different time zone, this is the solution for that.
// first line of PHP
$defaultTimeZone = ‘UTC’ ;
if( date_default_timezone_get ()!= $defaultTimeZone )) date_default_timezone_set ( $defaultTimeZone );

// somewhere in the code
function _date ( $format = «r» , $timestamp = false , $timezone = false )
$userTimezone = new DateTimeZone (!empty( $timezone ) ? $timezone : ‘GMT’ );
$gmtTimezone = new DateTimeZone ( ‘GMT’ );
$myDateTime = new DateTime (( $timestamp != false ? date ( «r» ,(int) $timestamp ): date ( «r» )), $gmtTimezone );
$offset = $userTimezone -> getOffset ( $myDateTime );
return date ( $format , ( $timestamp != false ?(int) $timestamp : $myDateTime -> format ( ‘U’ )) + $offset );
>

/* Example */
echo ‘System Date/Time: ‘ . date ( «Y-m-d | h:i:sa» ). ‘
‘ ;
echo ‘New York Date/Time: ‘ . _date ( «Y-m-d | h:i:sa» , false , ‘America/New_York’ ). ‘
‘ ;
echo ‘Belgrade Date/Time: ‘ . _date ( «Y-m-d | h:i:sa» , false , ‘Europe/Belgrade’ ). ‘
‘ ;
echo ‘Belgrade Date/Time: ‘ . _date ( «Y-m-d | h:i:sa» , 514640700 , ‘Europe/Belgrade’ ). ‘
‘ ;
?>
This is the best and fastest solution for this problem. Working almost identical to date() function only as a supplement has the time zone option.

For Microseconds, we can get by following:

echo date(‘Ymd His’.substr((string)microtime(), 1, 8).’ e’);

Thought, it might be useful to someone !

this how you make an HTML5 tag correctly

in the «datetime» attribute you should put a machine-readable value which represent time , the best value is a full time/date with ISO 8601 ( date(‘c’) ) . the attr will be hidden from users

and it doesn’t really matter what you put as a shown value to the user,, any date/time format is okay !

This is very good for SEO especially search engines like Google .

To get one month back, then simply write:

«`
$oneMonthBack = date( DateTime::ISO8601, strtotime(‘-1 month’ ));
«`

// results (for eg.)
// 2021-12-21T13:44:05+0000

Note that some formatting options are different from MySQL.
For example using a 24 hour notation without leading zeros is the option ‘%G’ in PHP but ‘%k’ in MySQL.
When using dynamically generated date formatting string, be careful to generate the correct options for either PHP or MySQL.

The following function will return the date (on the Gregorian calendar) for Orthodox Easter (Pascha). Note that incorrect results will be returned for years less than 1601 or greater than 2399. This is because the Julian calendar (from which the Easter date is calculated) deviates from the Gregorian by one day for each century-year that is NOT a leap-year, i.e. the century is divisible by 4 but not by 10. (In the old Julian reckoning, EVERY 4th year was a leap-year.)

This algorithm was first proposed by the mathematician/physicist Gauss. Its complexity derives from the fact that the calculation is based on a combination of solar and lunar calendars.

function getOrthodoxEaster ( $date ) <
/*
Takes any Gregorian date and returns the Gregorian
date of Orthodox Easter for that year.
*/
$year = date ( «Y» , $date );
$r1 = $year % 19 ;
$r2 = $year % 4 ;
$r3 = $year % 7 ;
$ra = 19 * $r1 + 16 ;
$r4 = $ra % 30 ;
$rb = 2 * $r2 + 4 * $r3 + 6 * $r4 ;
$r5 = $rb % 7 ;
$rc = $r4 + $r5 ;
//Orthodox Easter for this year will fall $rc days after April 3
return strtotime ( «3 April $year + $rc days» );
>
?>

It’s common for us to overthink the complexity of date/time calculations and underthink the power and flexibility of PHP’s built-in functions. Consider http://php.net/manual/en/function.date.php#108613

function get_time_string ( $seconds )
return date ( ‘H:i:s’ , strtotime ( «2000-01-01 + $seconds SECONDS» ));
>

FYI: there’s a list of constants with predefined formats on the DateTime object, for example instead of outputting ISO 8601 dates with:

echo date ( DateTime :: ISO8601 );
?>

instead, which is much easier to read.

In order to define leap year you must considre not only that year can be divide by 4!

if (year is not divisible by 4) then (it is a common year)
else if (year is not divisible by 100) then (it is a leap year)
else if (year is not divisible by 400) then (it is a common year)
else (it is a leap year)

So the code should look like this:

Most spreadsheet programs have a rather nice little built-in function called NETWORKDAYS to calculate the number of business days (i.e. Monday-Friday, excluding holidays) between any two given dates. I couldn’t find a simple way to do that in PHP, so I threw this together. It replicates the functionality of OpenOffice’s NETWORKDAYS function — you give it a start date, an end date, and an array of any holidays you want skipped, and it’ll tell you the number of business days (inclusive of the start and end days!) between them.

I’ve tested it pretty strenuously but date arithmetic is complicated and there’s always the possibility I missed something, so please feel free to check my math.

The function could certainly be made much more powerful, to allow you to set different days to be ignored (e.g. «skip all Fridays and Saturdays but include Sundays») or to set up dates that should always be skipped (e.g. «skip July 4th in any year, skip the first Monday in September in any year»). But that’s a project for another time.

function networkdays ( $s , $e , $holidays = array()) // If the start and end dates are given in the wrong order, flip them.
if ( $s > $e )
return networkdays ( $e , $s , $holidays );

// Find the ISO-8601 day of the week for the two dates.
$sd = date ( «N» , $s );
$ed = date ( «N» , $e );

// Find the number of weeks between the dates.
$w = floor (( $e — $s )/( 86400 * 7 )); # Divide the difference in the two times by seven days to get the number of weeks.
if ( $ed >= $sd ) < $w --; ># If the end date falls on the same day of the week or a later day of the week than the start date, subtract a week.

// Calculate net working days.
$nwd = max ( 6 — $sd , 0 ); # If the start day is Saturday or Sunday, add zero, otherewise add six minus the weekday number.
$nwd += min ( $ed , 5 ); # If the end day is Saturday or Sunday, add five, otherwise add the weekday number.
$nwd += $w * 5 ; # Add five days for each week in between.

// Iterate through the array of holidays. For each holiday between the start and end dates that isn’t a Saturday or a Sunday, remove one day.
foreach ( $holidays as $h ) $h = strtotime ( $h );
if ( $h > $s && $h < $e && date ( "N" , $h ) < 6 )
$nwd —;
>

$start = strtotime ( «1 January 2010» );
$end = strtotime ( «13 December 2010» );

// Add as many holidays as desired.
$holidays = array();
$holidays [] = «4 July 2010» ; // Falls on a Sunday; doesn’t affect count
$holidays [] = «6 September 2010» ; // Falls on a Monday; reduces count by one

echo networkdays ( $start , $end , $holidays ); // Returns 246

Or, if you just want to know how many work days there are in any given year, here’s a quick function for that one:

function workdaysinyear ( $y ) $j1 = mktime ( 0 , 0 , 0 , 1 , 1 , $y );
if ( date ( «L» , $j1 )) if ( date ( «N» , $j1 ) == 6 )
return 260 ;
elseif ( date ( «N» , $j1 ) == 5 or date ( «N» , $j1 ) == 7 )
return 261 ;
else
return 262 ;
>
else if ( date ( «N» , $j1 ) == 6 or date ( «N» , $j1 ) == 7 )
return 260 ;
else
return 261 ;
>
>

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