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CTimestamp

Package system.utils
Inheritance class CTimestamp
Since 1.0
Version $Id$
Source Code framework/utils/CTimestamp.php
CTimestamp represents a timestamp.

This class was adapted from the ADOdb Date Library, as part of the ADOdb abstraction library. The original source code was released under both BSD and GNU Lesser GPL library license, with the following copyright notice: Copyright (c) 2000, 2001, 2002, 2003, 2004 John Lim All rights reserved.

PHP native date static functions use integer timestamps for computations. Because of this, dates are restricted to the years 1901-2038 on Unix and 1970-2038 on Windows due to integer overflow for dates beyond those years. This library overcomes these limitations by replacing the native static function's signed integers (normally 32-bits) with PHP floating point numbers (normally 64-bits).

Dates from 100 A.D. to 3000 A.D. and later have been tested. The minimum is 100 A.D. as <100 will invoke the 2 => 4 digit year conversion. The maximum is billions of years in the future, but this is a theoretical limit as the computation of that year would take too long with the current implementation of getTimestamp.

PERFORMANCE For high speed, this library uses the native date static functions where possible, and only switches to PHP code when the dates fall outside the 32-bit signed integer range.

Public Methods

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MethodDescriptionDefined By
formatDate() Formats a timestamp to a date string. CTimestamp
get4DigitYear() Returns 4-digit representation of the year. CTimestamp
getDate() Returns the getdate() array. CTimestamp
getDayofWeek() Gets day of week, 0 = Sunday,... 6=Saturday. CTimestamp
getGMTDiff() Returns get local time zone offset from GMT CTimestamp
getTimestamp() Generates a timestamp. CTimestamp
isLeapYear() Checks for leap year, returns true if it is. No 2-digit year check. Also CTimestamp
isValidDate() Checks to see if the year, month, day are valid combination. CTimestamp
isValidTime() Checks to see if the hour, minute and second are valid. CTimestamp

Protected Methods

Hide inherited methods

MethodDescriptionDefined By
digitCheck() Fix 2-digit years. Works for any century. CTimestamp

Method Details

digitCheck() method
protected static integer digitCheck(integer $y)
$y integer year
{return} integer change two digit year into multiple digits
Source Code: framework/utils/CTimestamp.php#126 (show)
protected static function digitCheck($y)
{
    if ($y < 100){
        $yr = (integer) date("Y");
        $century = (integer) ($yr /100);

        if ($yr%100 > 50) {
            $c1 = $century + 1;
            $c0 = $century;
        } else {
            $c1 = $century;
            $c0 = $century - 1;
        }
        $c1 *= 100;
        // if 2-digit year is less than 30 years in future, set it to this century
        // otherwise if more than 30 years in future, then we set 2-digit year to the prev century.
        if (($y + $c1) < $yr+30) $y = $y + $c1;
        else $y = $y + $c0*100;
    }
    return $y;
}

Fix 2-digit years. Works for any century. Assumes that if 2-digit is more than 30 years in future, then previous century.

formatDate() method
public static string formatDate(string $fmt, integer $d=false, boolean $is_gmt=false)
$fmt string format pattern
$d integer timestamp
$is_gmt boolean whether this is a GMT timestamp
{return} string formatted date based on timestamp $d
Source Code: framework/utils/CTimestamp.php#229 (show)
public static function formatDate($fmt,$d=false,$is_gmt=false)
{
    if ($d === false)
        return ($is_gmt)? @gmdate($fmt): @date($fmt);

    // check if number in 32-bit signed range
    if ((abs($d) <= 0x7FFFFFFF))
    {
        // if windows, must be +ve integer
        if ($d >= 0)
            return ($is_gmt)? @gmdate($fmt,$d): @date($fmt,$d);
    }

    $_day_power = 86400;

    $arr = self::getDate($d,true,$is_gmt);

    $year = $arr['year'];
    $month = $arr['mon'];
    $day = $arr['mday'];
    $hour = $arr['hours'];
    $min = $arr['minutes'];
    $secs = $arr['seconds'];

    $max = strlen($fmt);
    $dates = '';

    /*
        at this point, we have the following integer vars to manipulate:
        $year, $month, $day, $hour, $min, $secs
    */
    for ($i=0; $i < $max; $i++)
    {
        switch($fmt[$i])
        {
        case 'T': $dates .= date('T');break;
        // YEAR
        case 'L': $dates .= $arr['leap'] ? '1' : '0'; break;
        case 'r': // Thu, 21 Dec 2000 16:01:07 +0200

            // 4.3.11 uses '04 Jun 2004'
            // 4.3.8 uses  ' 4 Jun 2004'
            $dates .= gmdate('D',$_day_power*(3+self::getDayOfWeek($year,$month,$day))).', '
                . ($day<10?'0'.$day:$day) . ' '.date('M',mktime(0,0,0,$month,2,1971)).' '.$year.' ';

            if ($hour < 10) $dates .= '0'.$hour; else $dates .= $hour;

            if ($min < 10) $dates .= ':0'.$min; else $dates .= ':'.$min;

            if ($secs < 10) $dates .= ':0'.$secs; else $dates .= ':'.$secs;

            $gmt = self::getGMTDiff();
            $dates .= sprintf(' %s%04d',($gmt<=0)?'+':'-',abs($gmt)/36);
            break;

        case 'Y': $dates .= $year; break;
        case 'y': $dates .= substr($year,strlen($year)-2,2); break;
        // MONTH
        case 'm': if ($month<10) $dates .= '0'.$month; else $dates .= $month; break;
        case 'Q': $dates .= ($month+3)>>2; break;
        case 'n': $dates .= $month; break;
        case 'M': $dates .= date('M',mktime(0,0,0,$month,2,1971)); break;
        case 'F': $dates .= date('F',mktime(0,0,0,$month,2,1971)); break;
        // DAY
        case 't': $dates .= $arr['ndays']; break;
        case 'z': $dates .= $arr['yday']; break;
        case 'w': $dates .= self::getDayOfWeek($year,$month,$day); break;
        case 'l': $dates .= gmdate('l',$_day_power*(3+self::getDayOfWeek($year,$month,$day))); break;
        case 'D': $dates .= gmdate('D',$_day_power*(3+self::getDayOfWeek($year,$month,$day))); break;
        case 'j': $dates .= $day; break;
        case 'd': if ($day<10) $dates .= '0'.$day; else $dates .= $day; break;
        case 'S':
            $d10 = $day % 10;
            if ($d10 == 1) $dates .= 'st';
            else if ($d10 == 2 && $day != 12) $dates .= 'nd';
            else if ($d10 == 3) $dates .= 'rd';
            else $dates .= 'th';
            break;

        // HOUR
        case 'Z':
            $dates .= ($is_gmt) ? 0 : -self::getGMTDiff(); break;
        case 'O':
            $gmt = ($is_gmt) ? 0 : self::getGMTDiff();

            $dates .= sprintf('%s%04d',($gmt<=0)?'+':'-',abs($gmt)/36);
            break;

        case 'H':
            if ($hour < 10) $dates .= '0'.$hour;
            else $dates .= $hour;
            break;
        case 'h':
            if ($hour > 12) $hh = $hour - 12;
            else {
                if ($hour == 0) $hh = '12';
                else $hh = $hour;
            }

            if ($hh < 10) $dates .= '0'.$hh;
            else $dates .= $hh;
            break;

        case 'G':
            $dates .= $hour;
            break;

        case 'g':
            if ($hour > 12) $hh = $hour - 12;
            else {
                if ($hour == 0) $hh = '12';
                else $hh = $hour;
            }
            $dates .= $hh;
            break;
        // MINUTES
        case 'i': if ($min < 10) $dates .= '0'.$min; else $dates .= $min; break;
        // SECONDS
        case 'U': $dates .= $d; break;
        case 's': if ($secs < 10) $dates .= '0'.$secs; else $dates .= $secs; break;
        // AM/PM
        // Note 00:00 to 11:59 is AM, while 12:00 to 23:59 is PM
        case 'a':
            if ($hour>=12) $dates .= 'pm';
            else $dates .= 'am';
            break;
        case 'A':
            if ($hour>=12) $dates .= 'PM';
            else $dates .= 'AM';
            break;
        default:
            $dates .= $fmt[$i]; break;
        // ESCAPE
        case "\\":
            $i++;
            if ($i < $max) $dates .= $fmt[$i];
            break;
        }
    }
    return $dates;
}

Formats a timestamp to a date string.

get4DigitYear() method
public static integer get4DigitYear(integer $y)
$y integer year
{return} integer 4-digit representation of the year
Source Code: framework/utils/CTimestamp.php#153 (show)
public static function get4DigitYear($y)
{
    return self::digitCheck($y);
}

Returns 4-digit representation of the year.

getDate() method
public static array getDate(integer $d=false, boolean $fast=false, boolean $gmt=false)
$d integer original date timestamp. False to use the current timestamp.
$fast boolean false to compute the day of the week, default is true
$gmt boolean true to calculate the GMT dates
{return} array an array with date info.
Source Code: framework/utils/CTimestamp.php#177 (show)
public static function getDate($d=false,$fast=false,$gmt=false)
{
    if($gmt)
    {
        $tz = date_default_timezone_get();
        date_default_timezone_set('GMT');
        $result = getdate($d);
        date_default_timezone_set($tz);
    }
    else
    {
        $result = getdate($d);
    }
    return $result;
}

Returns the getdate() array.

getDayofWeek() method
public static integer getDayofWeek(integer $year, integer $month, integer $day)
$year integer year
$month integer month
$day integer day
{return} integer day of week
Source Code: framework/utils/CTimestamp.php#57 (show)
public static function getDayofWeek($year, $month, $day)
{
    /*
    Pope Gregory removed 10 days - October 5 to October 14 - from the year 1582 and
    proclaimed that from that time onwards 3 days would be dropped from the calendar
    every 400 years.

    Thursday, October 4, 1582 (Julian) was followed immediately by Friday, October 15, 1582 (Gregorian).
    */
    if ($year <= 1582)
    {
        if ($year < 1582 ||
            ($year == 1582 && ($month < 10 || ($month == 10 && $day < 15))))
        {
            $greg_correction = 3;
        }
        else
        {
            $greg_correction = 0;
        }
    }
    else
    {
        $greg_correction = 0;
    }

    if($month > 2)
        $month -= 2;
    else
    {
        $month += 10;
        $year--;
    }

    $day =  floor((13 * $month - 1) / 5) +
            $day + ($year % 100) +
            floor(($year % 100) / 4) +
            floor(($year / 100) / 4) - 2 *
            floor($year / 100) + 77 + $greg_correction;

    return $day - 7 * floor($day / 7);
}

Gets day of week, 0 = Sunday,... 6=Saturday. Algorithm from PEAR::Date_Calc

getGMTDiff() method
public static integer getGMTDiff()
{return} integer get local time zone offset from GMT
Source Code: framework/utils/CTimestamp.php#161 (show)
public static function getGMTDiff()
{
    static $TZ;
    if (isset($TZ)) return $TZ;

    $TZ = mktime(0,0,0,1,2,1970) - gmmktime(0,0,0,1,2,1970);
    return $TZ;
}

getTimestamp() method
public static integer|float getTimestamp(integer $hr, integer $min, integer $sec, integer $mon=false, integer $day=false, integer $year=false, boolean $is_gmt=false)
$hr integer hour
$min integer minute
$sec integer second
$mon integer month
$day integer day
$year integer year
$is_gmt boolean whether this is GMT time
{return} integer|float a timestamp given a local time. Originally by jackbbs.
Source Code: framework/utils/CTimestamp.php#383 (show)
public static function getTimestamp($hr,$min,$sec,$mon=false,$day=false,$year=false,$is_gmt=false)
{
    if ($mon === false)
        return $is_gmt? @gmmktime($hr,$min,$sec): @mktime($hr,$min,$sec);
    return $is_gmt ? @gmmktime($hr,$min,$sec,$mon,$day,$year) : @mktime($hr,$min,$sec,$mon,$day,$year);
}

Generates a timestamp. Not a very fast algorithm - O(n) operation. Could be optimized to O(1).

isLeapYear() method
public static boolean isLeapYear(integer $year)
$year integer year to check
{return} boolean true if is leap year
Source Code: framework/utils/CTimestamp.php#106 (show)
public static function isLeapYear($year)
{
    $year = self::digitCheck($year);
    if ($year % 4 != 0)
        return false;

    if ($year % 400 == 0)
        return true;
    // if gregorian calendar (>1582), century not-divisible by 400 is not leap
    else if ($year > 1582 && $year % 100 == 0 )
        return false;
    return true;
}

Checks for leap year, returns true if it is. No 2-digit year check. Also handles julian calendar correctly.

isValidDate() method
public static boolean isValidDate(integer $y, integer $m, integer $d)
$y integer year
$m integer month
$d integer day
{return} boolean true if valid date, semantic check only.
Source Code: framework/utils/CTimestamp.php#200 (show)
public static function isValidDate($y,$m,$d)
{
    return checkdate($m, $d, $y);
}

Checks to see if the year, month, day are valid combination.

isValidTime() method (available since v1.0.5)
public static boolean isValidTime(integer $h, integer $m, integer $s, boolean $hs24=true)
$h integer hour
$m integer minute
$s integer second
$hs24 boolean whether the hours should be 0 through 23 (default) or 1 through 12.
{return} boolean true if valid date, semantic check only.
Source Code: framework/utils/CTimestamp.php#214 (show)
public static function isValidTime($h,$m,$s,$hs24=true)
{
    if($hs24 && ($h < 0 || $h > 23) || !$hs24 && ($h < 1 || $h > 12)) return false;
    if($m > 59 || $m < 0) return false;
    if($s > 59 || $s < 0) return false;
    return true;
}

Checks to see if the hour, minute and second are valid.