I'm being told that this below method of calculating the user's local time is sometimes not working. What's the best way to do this in PHP? What do you do?
public function getTimeOffset ($time) {
$this->_cacheTimeOffset();
if ($this->timeOffsetExecuted) {
$d = date("O");
$neg = 1;
if (substr($d, 0, 1) == "-") {
$neg = -1;
$d = substr($d, 1);
}
$h = substr($d, 0, 2)*3600;
$m = substr($d, 2)*60;
return $time + ($neg * ($h + $m) * -1) + (($this->timeOffset + $this->getDstInUse()) * 3600);
}
return $time;
}
Use the DateTime extension, such as DateTime::getOffset,
or DateTimeZone::getOffset
Some countries might have perform several timezone update,
this method DateTimeZone::getTransitions reveal the transition history
Just answered a very similar question over here. I recommend you check that one out; I explained the two preferred ways of doing timezone offset calculation (using simple math, and then the datetimezone and datetime classes) pretty thoroughly.
The first way would be the easiest
(and most logical) way, and that is to
store their offset (if you already
have it, that is) and multiply that by
3600 (1 hour in seconds), and then add
that value to the current unix timestamp to get their final time of
running.
Another way to do it is to use the
DateTime and DateTimeZone classes.
How these two classes work, as shown
here, is that you create two
DateTimeZone objects, one with your
timezone and one with theirs; create
two DateTime objects with the first
parameters being "now" and the
second being the reference to the
DateTimeZone objects above
(respectively); and then call the
getOffset method on your timezone
object passing their timezone object
as the first parameter, ultimately
getting you the offset in seconds that
can be added to the current unix
timestamp to get the time that their
job needs to run.
date('Z');
returns the UTC offset in seconds.
A quick solution:
<?php echo date('g:i a', strtotime("now + 10 hours 30 minutes")); ?>
Related
I have a given time and i need to create another time base on another given time. Let suppose i have given 4:00:00 AM, and another time is 2:00:00 , my result should be 6:00:00 AM, and 2:00:00 AM(based on condition).
this is what i am using but its not giving correect result.
if($data['turn_on_before_or_after'] == 'before'){
$time = strtotime($data['sunset']) - strtotime($data['variation_turn_on']);
$dataNew['final_turn_on'] = date('h:m:s',$time);
}
if($data['turn_on_before_or_after'] == 'after'){
$time = strtotime($data['sunset']) + strtotime($data['variation_turn_on']);
$dataNew['final_turn_on'] = date('h:m:s',$time);
}
Recommendation: use strtotime(). It will takes the date/time/datetime string and convert it to an integer; starting at the unix epoch. So 2AM would be 7200 and 4AM would be 14400; add those integers together and use date('H', $result) would convert the integer back into a time string. Boosh, win!
Opinion: many people will say unix timestamp is hard to use 'cause it is not human readable;I'd rather my logic be easy to read than the output. As the output only happens at the end of processing.
I recreated your scenario, but instead of using strtotime I used the DateTime object.
Your main problem is that your first date ($data['sunset']) must be considered as a real date, but your second date ($data['variation_turn_on']) must be considered as an interval. Because of this, and after looking at the DateInterval object constructor, you notice that you can create an interval using sscanf from your initial string. After creating that interval, all you have to do is to use the methods from the DateTime class to simply add or substract intervals from a specific date.
Here is the code I wrote to obtain the results you expect (6:00:00 AM and 2:00:00 AM) :
<?php
/* Initial parameters */
$data['turn_on_before_or_after'] = "before";
$data['sunset'] = "4:00:00 AM";
$data['variation_turn_on'] = "2:00:00";
/* Creating a list with your variation values */
list($hours, $minutes, $seconds) = sscanf($data['variation_turn_on'], '%d:%d:%d');
/* Creating the interval (here is the magic) */
$intervale = new DateInterval(sprintf('PT%dH%dM%dS', $hours, $minutes, $seconds));
/* Creating a DateTime object from your sunset time */
$date = new DateTime($data['sunset']);
/* Ternary for simplification, substract if before, add if everything else, you may use an if statement here */
$data['turn_on_before_or_after'] == 'before' ? $date->sub($intervale) : $date->add($intervale);
/* Printing the result */
echo $date->format('h:i:s A');
I have here a mysql query that get the average of the column(the column data type is 'time'). The column values for example are:
00:00:55, 00:00:59, 00:01:03
SELECT AVG(TIME_TO_SEC(column_name)) FROM table_name)AS average_result
In my Php I formatted the result this way:
<?php foreach($display_average as $da){
echo date("H:i:s", ($da["average_result"]));
}
?>
Outputs: 08:00:59 instead of 00:00:59, Why does this starts with 08? Or did I miss something? Thanks!
Both PHP's date/time functions and MySQL's date/time data types handle wall clock timestamps, not durations; i.e. 00:00:55 means fifty-five seconds past midnight. This is not what you want; you couldn't handle durations longer than 23 hours, 59 minutes, 59 seconds, because the data types and functions you're using are handling clock time, which cannot exceed these values.
Your specific issue stems from timezone settings. Your larger issue is that you need to store simple integer values expressing elapsed seconds or minutes; not timestamps. To format that into a human readable string in PHP you can use the DateInterval class.
see php manul, about the date_default_timezone_set your timezone is +8
the default date.timezone of PHP is utc, u can change it to date.timezone = PRC
date_default_timezone_set('UTC');
echo date("H:i:s", 59);//00:00:59
//date_default_timezone_set('RPC');
//echo date("H:i:s", 59);//08:00:59
Always go for standard/formal approaches. But if anyhow you need it custom, then you can do almost everything with programming. Here we go
Get your time as numbers (number of seconds in your time filed) from database as
SELECT
AVG
(
HOUR(column_name) * 3600
+ MINUTE(column_name) * 60
+ SECOND(column_name)
) AS numeric_average_result FROM table_name
Now you can convert number of seconds to proper time as
foreach($display_average as $da)
{
$r = numToTime($da["numeric_average_result"]);
echo "<br>".$r;
}
function numToTime($num)
{
$seconds = $num%60;
$num = (int)($num/60);
$minutes = $num%60;
$hours = (int)($num/60);
return make2digit($hours).":".make2digit($minutes).":".make2digit($seconds);
}
function make2digit($val)
{
if(strlen($val) == 1)
return "0".$val;
else
return $val;
}
I have a PHP DateTime object with microseconds created as follows:
$time = microtime(true);
$microseconds = sprintf('%06d', ($time - floor($time)) * 1000000);
$dt = new DateTime(date('Y-m-d H:i:s.' . $microseconds, $time));
How can I modify the microseconds value of $dt, without creating a completely new DateTime instance?
You can't.
There are three methods that can modify the value of a DateTime instance: add, sub and modify. We can rule out add and sub immediately because they work in terms of a DateInterval which does not have sub-second precision.
modify accepts a string in one of the standard recognized formats. Of those formats, only the relative ones are of interest here because the other ones work in an absolute manner; and there is no relative format that allows tweaking the msec part (that unit is not recognized).
as of PHP 7.1
DateTime::setTime() supports microseconds.
This seems to have been available since 7.1.0-rc4
$dt = new DateTime('2020-01-01 0:00');
$dt->modify('+500 ms'); // Milliseconds.
$dt->modify('+123456 usec'); // Microseconds.
$dt->modify('+123456 microseconds'); // This works too.
It's mentioned here in the manual.
Manually creating a DateTime object with micro seconds:
$d = new DateTime("15-07-2014 18:30:00.111111");
Getting a DateTime object of the current time with microseconds:
$d = date_format(new DateTime(),'d-m-Y H:i:s').substr((string)microtime(), 1, 8);
Difference between two DateTime objects in microseconds (e.g. returns: 2.218939)
//Returns the difference, in seconds, between two datetime objects including
//the microseconds:
function mdiff($date1, $date2){
$date1sec = strtotime($date1->format('d-m-Y H:i:s.u'));
$date2sec = strtotime($date2->format('d-m-Y H:i:s.u'));
//Absolute val of Date 1 in seconds from (EPOCH Time) - Date 2 in seconds from (EPOCH Time)
$secdiff = abs($date1sec-$date2sec);
//Creates variables for the microseconds of date1 and date2
$micro1 = $date1->format("u");
$micro2 = $date2->format("u");
if (($date1sec<$date2sec && $micro1>$micro2)||($date1sec>$date2sec && $micro1<$micro2)){
$microdiff = abs(1000000 - abs($micro1-$micro2));
$secdiff = $secdiff - 1;
} else {
$microdiff = abs($micro1 - $micro2);
}
//Creates the variable that will hold the seconds (?):
$difference = $secdiff.".".$microdiff;
return $difference;
}
Essentially it finds the difference for the DateTime Objects using strtotime and then adding the extra microseconds on.
Do you need me to create add and sub?
i had a similar problem and ended up having to wrap the whole thing
https://gist.github.com/chandeeland/9817516
For the people only in need to zero-out microseconds (I had to because of database layer) here's the snippet I ended up using:
$format = "Y-m-d H:i:s e";
$now = (new \DateTime())->format($format);
$dateTime = \DateTime::createFromFormat($format, $now);
Note that using $format = 'c', ISO 8601, will not work, as explained here (https://stackoverflow.com/a/10478469/8119317).
In PHP, you can tell if a given date is during the Daylight Savings Time period by using something like this:
$isDST = date("I", $myDate); // 1 or 0
The problem is that this only tells you whether that one point in time is in DST. Is there a reliable way to check whether DST is in effect at any time in that timezone?
Edit to clarify:
Brisbane, Australia does not observe daylight savings at any time of the year. All year around, it is GMT+10.
Sydney, Australia does, from October to March when it changes from GMT+10 to GMT+11.
I'm wondering if there would be some existing method, or a way to implement a method which works as such:
timezoneDoesDST('Australia/Brisbane'); // false
timezoneDoesDST('Australia/Sydney'); // true
I've found a method which works using PHP's DateTimezone class (PHP 5.2+)
function timezoneDoesDST($tzId) {
$tz = new DateTimeZone($tzId);
$trans = $tz->getTransitions();
return ((count($trans) && $trans[count($trans) - 1]['ts'] > time()));
}
or, if you're running PHP 5.3+
function timezoneDoesDST($tzId) {
$tz = new DateTimeZone($tzId);
return count($tz->getTransitions(time())) > 0;
}
The getTransitions() function gives you information about each time the offset changes for a timezone. This includes historical data (Brisbane had daylight savings in 1916.. who knew?), so this function checks if there's an offset change in the future or not.
Actually nickf method didn't works for me so I reworked it a little ...
/**
* Finds wherever a TZ is experimenting dst or not
* #author hertzel Armengol <emudojo # gmail.com>
* #params string TimeZone -> US/Pacific for example
*
*/
function timezoneExhibitsDST($tzId) {
$tz = new DateTimeZone($tzId);
$date = new DateTime("now",$tz);
$trans = $tz->getTransitions();
foreach ($trans as $k => $t)
if ($t["ts"] > $date->format('U')) {
return $trans[$k-1]['isdst'];
}
}
// Usage
var_dump(timezoneExhibitsDST("US/Pacific")); --> prints false
var_dump(timezoneExhibitsDST("Europe/London")); --> prints false
var_dump(timezoneExhibitsDST("America/Chicago")); --> prints false
same function call will return true in 1 month (March) hope it helps
DateTimeZone::getTransitions might help.
You could probably wing it:
$hasDst = date("I", strtotime('June 1')) !== date("I", strtotime('Jan 1'));
Otherwise you'd need to parse the text-based zoneinfo data files.
I don't think so, but since almost every country that observes DST changes its time for an entire season or two, you could try to test 4 points during any given year.
For example, test date("I", $date) for 2009/01/01, 2009/04/01, 2009/07/01 and 2009/10/01. If that timezone falls into DST, then at least one of those dates will return 1.
date has to be on the user/server timezone for it to work, and you can't use a range with date as you do with getTransitions
In Actionscript, the Unix timestamp in milliseconds is obtainable like this:
public static function getTimeStamp():uint
{
var now:Date = new Date();
return now.getTime();
}
The doc clearly states the following:
getTime():Number Returns the number of
milliseconds since midnight January 1,
1970, universal time, for a Date
object.
When I trace it, it returns the following:
824655597
So, 824655597 / 1000 / 60 / 60 / 24 / 365 = 0.02 years.
This is obviously not correct, as it should be around 39 years.
Question #1: What's wrong here?
Now, onto the PHP part: I'm trying to get the timestamp in milliseconds there as well. The microtime() function returns either a string (0.29207800 1246365903) or a float (1246365134.01), depending on the given argument. Because I thought timestamps were easy, I was going to do this myself. But now that I have tried and noticed this float, and combine that with my problems in Actionscript I really have no clue.
Question #2: how should I make it returns the amount of milliseconds in a Unix timestamp?
Timestamps should be so easy, I'm probably missing something.. sorry about that. Thanks in advance.
EDIT1: Answered the first question by myself. See below.
EDIT2: Answered second question by myself as well. See below. Can't accept answer within 48 hours.
I used unsigned integer as the return type of the function. This should be Number.
public static function getTimeStamp():Number
{
var now:Date = new Date();
return now.getTime();
}
Think I got the function for getting milliseconds in PHP5 now.
function msTimeStamp() {
return round(microtime(1) * 1000);
}
For actionscript3, new Date().getTime() should work.
In PHP you can simply call time() to get the time passed since January 1 1970 00:00:00 GMT in seconds. If you want milliseconds just do (time()*1000).
If you use microtime() multiply the second part with 1000 to get milliseconds. Multiply the first part with 1000 to get the milliseconds and round that. Then add the two numbers together. Voilá.
Use this:
intval(microtime(true)*1000)
To normalize a timestamp as an integer with milliseconds between Javascript, Actionscript, and PHP
Javascript / Actionscript:
function getTimestamp(){
var d = new Date();
return Date.UTC(d.getFullYear(), d.getMonth(), d.getDate(), d.getHours(), d.getMinutes(), d.getSeconds(), d.getMilliseconds()).valueOf();
}
PHP:
function getTimestamp(){
$seconds = microtime(true); // true = float, false = weirdo "0.2342 123456" format
return round( ($seconds * 1000) );
}
See PHP note at "ben at sixg dot com's" comment at: http://www.php.net/manual/en/function.gmmktime.php
EXCERPT:
For most intents and purposes you can imagine that mktime() first converts your input parameters to GMT and then calls gmmktime() which produces a GMT timestamp.
So, time() always will return the same thing at the same actual moment, anywhere in the world.
gmmktime() and mktime(), when given specific time parameters, convert those time parameters FROM the appropriate timezone (GMT for gmmktime(), local time for mktime()), before computing the appropriate timestamp.
UPDATE:
On some versions of PHP, the timestamp with milliseconds is too large to display as a string. So use the sprintf function to get the string value:
PHP
function getTimestamp($asString=false){
$seconds = microtime(true); // false = int, true = float
$stamp = round($seconds * 1000);
if($asString == true){
return sprintf('%.0f', $stamp);
} else {
return $stamp;
}
}
microtime() in php5 returns unix timestamp with microseconds as per microtime() and if the get_as_float argument is not provided, it gives you a string formatted as "msec sec" so the first part is the millisecond part and the second is the second part. Just split it in two and you get the two parts of the timestamp
Simple answer for PHP:
function exact_time() {
$t = explode(' ',microtime());
return ($t[0] + $t[1]);
}
To get millisecond timestamp from PHP DateTime object:
<?php
date_default_timezone_set('UTC');
$d = new \DateTime('some_data_string');
$mts = $d->getTimestamp().substr($d->format('u'),0,3); // millisecond timestamp
PHP 7
This function has its return type declared.
function timestamp_ms(): int {
$times = gettimeofday();
$seconds = strval($times["sec"]);
$milliseconds = strval(floor($times["usec"]/1000));
$missingleadingzeros = 3-strlen($milliseconds);
if($missingleadingzeros >0){
for($i = 0; $i < $missingleadingzeros; $i++){
$milliseconds = '0'.$milliseconds;
}
}
return intval($seconds.$milliseconds);
}
PHP 5
function timestamp_ms() {
$times = gettimeofday();
$seconds = strval($times["sec"]);
$milliseconds = strval(floor($times["usec"]/1000));
$missingleadingzeros = 3-strlen($milliseconds);
if($missingleadingzeros >0){
for($i = 0; $i < $missingleadingzeros; $i++){
$milliseconds = '0'.$milliseconds;
}
}
return intval($seconds.$milliseconds);
}
when you need the millisecond in str format, I think you should use:
public function get_millisecond() {
list($milliPart, $secondPart) = explode(' ', microtime());
$milliPart = substr($milliPart, 2, 3);
return $secondPart . $milliPart;
}
this will fix the bug int some get millisecond example where the milli part is like : 0.056. some example convert the milli part to float, your will get 56 instead of 056. I think some one want 056.
especially when you need the millisecond to order some data.
hope will help. :)
I recently had this problem to get a timestamp in milliseconds. To just multiply the unix timestamp by 1000 did not resolve the problem because i had to compare two database entrys very precicely. Aparently the php datetime object can´t handle milliseconds/microseconds but its stored in the datetime string anyway. So here is my solution:
$dateObject = new \DateTime('2015-05-05 12:45:15.444', new \DateTimeZone('Europe/London'));
$millis = $dateObject->format('v');
echo $dateObject->getTimestamp()*1000+$millis;
This should also work with microseconds if you use format->('u') (and of course multiply the timestamp by 1000000) instead. I hope you find this useful.
Something like this:
$mili_sec_time = $_SERVER['REQUEST_TIME_FLOAT'] * 1000;
Gives float type representing miliseconds from UNIX epoch to starts of the request.
$timestamp = str_replace(".","",number_format((float)microtime(true),2,'.',''));