A very comprehensive summary of PHP date and time operations_php skills

Before explaining the examples, let’s introduce a few core functions:
mktime function
The mktime() function returns the Unix timestamp of a date.
The argument always represents a GMT date, so is_dst has no effect on the result.
The parameters can be left empty in order from right to left, and the empty parameters will be set to the corresponding current GMT value.
Syntax: mktime(hour,minute,second,month,day,year,is_dst)
Parameters                                                                                 
hour Optional. Specified hours. minute Optional. Specified minutes.
second is optional. Specifies seconds.
month is optional. Specifies the numeric month.
day is optional. Specify days.
year is optional. Specified year. On some systems, legal values ​​are between 1901 - 2038. However, this limitation no longer exists in PHP 5.
is_dst Optional. Set to 1 if the time is during Daylight Saving Time (DST), 0 otherwise, or -1 if unknown.
As of 5.1.0, the is_dst parameter is deprecated. Therefore the new time zone handling features should be used.
Example: The mktime() function is useful for date operations and validation. It can automatically correct out-of-bounds input:

<&#63;php 
echo(date("M-d-Y",mktime(0,0,0,12,36,2001))); 
echo(date("M-d-Y",mktime(0,0,0,14,1,2001))); 
echo(date("M-d-Y",mktime(0,0,0,1,1,2001))); 
echo(date("M-d-Y",mktime(0,0,0,1,1,99))); 
&#63;> 

Output:

Jan-05-2002 
Feb-01-2002 
Jan-01-2001 
Jan-01-1999 

strtotime function The
strtotime() function parses any English text datetime description into a Unix timestamp. Syntax:
strtotime(time,now)
Parameter Description
time specifies the time string to be parsed. now is the timestamp used to calculate the return value. If this parameter is omitted, the current time is used. 
One week later: strtotime(" 1 week") ;
One week ago: strtotime("-1 week") ;
After one month: strtotime(" 1 months") ;
One day later: strtotime(" 1 days") ;
After 30 seconds strtotime( " 30 seconds " );
After 20 minutes strtotime( " 20 minutes " );
12 hours later strtotime( " 12 hours " );

date function The date() function formats a local time/date.
Grammar
date(format,timestamp)
date_default_timezone_set function
The date_default_timezone_set() function sets the default time zone used for all date/time functions in scripts.
date_default_timezone_set(timezone)

Example

The first case is that there is no database, and if you just compare the obtained date values, you have to use PHP’s time and date function to calculate it, as follows:

For example, to calculate how many days are left from 2015-9-5 to 2015-9-18:

<&#63;php 
$startdate=strtotime("2015-9-5"); 
$enddate=strtotime("2015-9-18"); //上面的php时间日期函数已经把日期变成了时间戳，就是变成了秒。这样只要让两数值相减，然后把秒变成天就可以了，比较的简单，如下： 
$days=round(($enddate-$startdate)/3600/24) ; 
echo $days; //days为得到的天数; 
&#63;> 

The second type Children’s growth

 <&#63; 
date_default_timezone_set('Asia/Shanghai'); 
//以上一句为设置时区，其实不设也行，但是zde debug的时候会有提示，说什么不安全的函数…添上吧。 
 
echo date('Y-m-d H:i:s').' 今天是'.date('Y').'年的第'.date('W').'周'; 
 
$stime='2005-11-03 10:08'; 
echo "<br/><br/>***自出生(<font color=blue>$stime</font>)以来…：<br/><br/>"; 
echo "今天是第<font color=red><b>".Lnbsp(daysofnow($stime),3)."</b></font>天<br/>"; 
echo "今天是第<font color=red><b>".Lnbsp(weeksofnow($stime),3)."</b></font>周<br/>"; 
echo "今天是第<font color=red><b>".Lnbsp(monthsofnow($stime),3)."</b></font>个月<br/>"; 
echo "今天是第<font color=red><b>".Lnbsp(yearsofnow($stime),3)."</b></font>年<br/>"; 
/* 
$output=sprintf(" 今天是第<font color=red><b>%03d</b></font>天<br/>今天是第< font color=red><b>%03d</b></font>周<br/>今天是第< font color=red><b>%03d</b></font>个月<br/>今天是第< font color=red><b>%03d</b></font>年<br/& gt;",daysofnow($stime),weeksofnow($stime),monthsofnow($stime),yearsofnow($stime)); 
echo $output; 
*/ 
 
function weeksofnow($stime) 
{ 
 $ftime=strtotime($stime); 
 $fweeks=date('w',$ftime); 
 if ($fweeks==0) $fweeks=7; 
 $nweeks=date('w'); 
 if ($nweeks==0) $nweeks=7; 
 $ftemp=strtotime(date('Y-m-d 00:00:00',$ftime))-$fweeks*60*60*24; 
 $ntemp=strtotime(date('Y-m-d 00:00:00',time()))+(7-$nweeks)*60*60*24; 
 //echo date('w',$ftemp)."<br/>....<br/>".date('w',$ntemp)."<br/>"; 
 return ($ntemp-$ftemp)/60/60/24/7; 
} 
 
function daysofnow($stime) 
{ 
 $ftime=strtotime($stime); 
 return ceil(abs((time()-$ftime)/(60*60*24))); 
} 
 
function monthsofnow($stime) 
{ 
 $ftime=strtotime($stime); 
 $fmonth=date('m',$ftime); 
 $fyear=date('Y',$ftime); 
 $nmonth=date('m'); 
 $nyear=date('Y'); 
 $result=($nyear-$fyear)*12+$nmonth-$fmonth+1; 
 return $result; 
} 
 
function yearsofnow($stime) 
{ 
 $ftime=strtotime($stime); 
 $fyear=date('Y',$ftime); 
 $nyear=date('Y'); 
 return $nyear-$fyear+1; 
} 
 
// 下面的函数只是加空格用的，不是核心内容，只为美观 
function Lnbsp($data,$num) 
{ 
 $result=trim($data); 
 for($i=$num;$i>=strlen($data);$i--) { 
 $result=' '.$result; 
 } 
 return $result; 
} 
&#63;> 

The third situation: For the dates of tomorrow, next month and next year, you can use the following code:

$tomorrow = date('Y-m-d',mktime (0,0,0,date("m"),date("d")+1,date("Y"))); 
$nextmonth = date('Y-m',mktime (0,0,0,date("m")+1,date("d")+1,date("Y"))); 
$nextyear = date('Y',mktime (0,0,0,date("m"),date("d"),date("Y")+1)); 
 
echo $tomorrow.'<br/>'; 
echo $nextmonth.'<br/>'; 
echo $nextyear.'<br/>'; 

The fourth situation: Working hours (excluding holidays)

<&#63; 
$startDate="2001-12-12"; 
$endDate="2002-11-1"; 
 
$holidayArr=array("05-01","05-02","10-01","10-01","10-02","10-03","10-04","10-05","01-26","01-27","01-28","01-29"); 
 //假期日期数组，比方国庆,五一,春节等 
$endWeek=2; 
 //周末是否双休.双休为2，仅仅星期天休息为1，没有休息为0 
 
$beginUX=strtotime($startDate); 
$endUX=strtotime($endDate); 
 
for($n=$beginUX;$n<=$endUX;$n=$n+86400){ 
 $week=date("w",$n); 
 $MonDay=date("m-d",$n); 
 if($endWeek){//去处周末休息 
 if($endWeek==2){ 
 if($week==0||$week==6) continue; 
 } 
 if($endWeek==1){ 
 if($week==0) continue; 
 } 
 } 
 if(in_array($MonDay,$holidayArr)) continue; 
 $totalHour+=10;//每天工作10小时 
} 
echo "开始日期：$startDate<BR>"; 
echo "结束日期：$endDate<BR>"; 
echo "共花了".$totalHour."小时"; 
&#63;> 

The fifth situation: give seconds to calculate hours

<&#63;php 
function transform($sec){ 
 
 $output = ''; 
 
 $hours = floor($sec / 3600); 
 $remainSeconds = $sec % 3600; 
 
 $minutes = floor($remainSeconds / 60); 
 $seconds = $sec - $hours * 3600 - $minutes * 60; 
 
 if($sec >= 3600){ 
 $output .= $hours.' h / '; 
 $output .= $minutes.' m / '; 
 } 
 
 if($sec >= 60 && $sec < 3600){ 
 $output .= $minutes.' m / '; 
 } 
 
 return $output .= $seconds.' s '; 
} 
 
echo transform(3231803); 
 
&#63;> 

The above are all examples of PHP date and time operations provided for you. I hope it will be helpful to your learning.