Research on the date processing function of gamma function php and the date processing function of uchome's function_coomon

Copy the code The code is as follows:

echo mktime(11,25,0,9,5,2010);//Same as time
echo microtime() ;
echo mktime(0,0,0,1,1,1970);
?>

The output here are 1283657290, 1283657100, 0.88533200 1283657290, -25200. Judging from the last value, we know that the timestamp returned here has been adjusted by the time zone, which is 0 o'clock on January 1, 1970 when I was in China. Greenwich has not yet reached 0 o'clock, so the time here will be a negative number. And the whole value is equal to -8*3600.
Look again

Copy the code The code is as follows:

echo date ("H i l d F" ,1283657100);
echo gmdate ("H i l d F" ,1283657100);
e cho strftime ("%Hh%M %A %d %b" ,1283657100);
//The way strftime() works is no different from date(), except that a percent sign % must be added in front of the special formatting characters.
echo strtotime("2010-9-5 11:25:00");
var_dump(getdate (time()));
?>

The output here is 11 25 Sunday 05 September, 03 25 Sunday 05 September, 11h25 Sunday 05 Sep, 1283657100, array(11) {
["seconds"]=>
int(9)
["minutes"]=>
int(39)
["hours"]=> ;
int(11)
["mday"]=>
int(5)
["wday"]=>
int(0)
["mon"]=>
int(9)
[ "year"]=>
int(2010)
["yday"]=>
int(247)
["weekday"]=>
string(6) "Sunday"
["month"]= >
string(9) "September"
[0]=>
int(1283657949)
}
Mainly look at the third output. The output here is at 11:25 on September 5, 2010 in China. What time is it in Greenwich? The time difference must also be taken into account here. And another strange thing here is that only gmdate does not issue a warning, and the rest have warnings that they cannot rely on the system's time zone. Imagine that, because gmdate only calculates Greenwich time, even if the system time zone is wrong, one plus and one subtraction will make it normal again.

Copy the code The code is as follows:

//Time formatting
function sgmdate($dateformat, $timestamp='', $format=0) {
global $_SCONFIG, $_SGLOBAL;
if(empty ($timestamp)) {
$timestamp = $_SGLOBAL['timestamp'];
}
$timeoffset = strlen($_SGLOBAL['member']['timeoffset'])>0?intval($_SGLOBAL['member ']['timeoffset']):intval($_SCONFIG['timeoffset']);
$result = '';
if($format) {
$time = $_SGLOBAL['timestamp'] - $timestamp;
if($time > 24*3600) {
$result = gmdate($dateformat, $timestamp + $timeoffset * 3600);
} elseif ($time > 3600) {
$result = intval($time/3600 ).lang('hour').lang('before');
} elseif ($time > 60) {
$result = intval($time/60).lang('minute').lang('before ');
} elseif ($time > 0) {
$result = $time.lang('second').lang('before');
} else {
$result = lang('now');
}
} else {
$result = gmdate($dateformat, $timestamp + $timeoffset * 3600);
}
return $result;
}

Let’s look directly at the contents of if($format){}, First, find the difference between the current time of the system and the time I passed in (usually the time in the database, such as 2010-9-4 21:00:00). If the time difference is within one day, the conclusion is drawn directly, such as two hours ago. If it is greater than 1 day, gmdate is called. I just don't understand it here. Why call this weird function instead of date($timestamp) directly? What the hell does this mean?
gmdate
When run in Finland (GMT +0200), the first line below prints "Jan 01 1998 00:00:00", while the second prints "Dec 31 1997 22:00:00".

Copy code The code is as follows:

echo date("M d Y H:i:s", mktime(0, 0, 0, 1, 1, 1998));
echo gmdate("M d Y H :i:s", mktime(0, 0, 0, 1, 1, 1998));
?>

That is to say, gmdate has considered the time difference. The standard time format will be output here, not days ago.
Next, focus on the functions in function_common of uchome

Copy the code The code is as follows:

//String time
function sstrtotime($string) {
global $_SGLOBAL, $_SCONFIG;
$time = '';
if($string) {
$time = strtotime($string);
if(gmdate('H:i', $_SGLOBAL['timestamp'] + $_SCONFIG['timeoffset'] * 3600) != date('H:i', $_SGLOBAL['timestamp'])) {
$time = $time - $_SCONFIG['timeoffset'] * 3600;
}
}
return $time;
}

Although there are very few functions in this function, it is very difficult for me to see it. This is to convert a time string into a timestamp. For example, what I input here is 2010 9 4 21:08, then the value of $time is the time difference from this time to January 1 1970 00:00:00 GMT. Here is the time difference to be considered. The value of $_SGLOBAL[''timestamp] is actually calculated in the same way as $time, but the values ​​may be slightly different. $_SCONFIG['timeoffset'] is in the config table, and its current value is 8. There is a situation where the system time zone is correct or incorrect, which needs to be checked through $_SCONFIG['timeoffset']. gmdate passes the incoming timestamp (the timestamp of the place where the program is run) through the system time zone to get the time in Greenwich at that time. If the system time zone is set correctly, then this is exactly one plus and one minus, which is equal to the following one (in fact, the value of $_SGLOBAL[''timestamp] here is irrelevant). If it is normal, then there is no need to change $time. If it is abnormal, then it needs to be reduced. But again, what the hell does this mean?

The above introduces the research on the date processing function of gamma function php and the date processing function in uchome's function_coomon, including the content of gamma function. I hope it will be helpful to friends who are interested in PHP tutorials.