I've been struggling quite a while with PHP's DateTime classes. My understanding is that a UNIX-timstamp is always in UTC, regardless of the timezone.
That's why I am quite confused with this code sample.
$date1 = new DateTime("#1351382400"); // Sun Oct 28 2012 02:00:00 GMT+2 (DST)
var_dump($date1->getTimestamp()); //prints: 1351382400
$date1->setTimezone(new DateTimeZone("Europe/Stockholm"););
var_dump($date1->getTimestamp()); //prints: 1351386000
As you can see setTimezone() changes the result of getTimestamp().
Is it expected that setTimezone() affects getTimestamp()?
The amount that you're off is 3600 seconds, or 1 hour.
I think that what you're seeing is because the date you picked is the end of Daylight Savings Time in Stockholm. If you use a different date, you don't get that effect:
$now = time();
echo " now: $now\n";
$date1 = new DateTime("#{$now}");
echo " date1 here: {$date1->getTimestamp()}\n";
$date1->setTimezone(new DateTimeZone("Europe/Stockholm"));
echo "date1 Stockholm: {$date1->getTimestamp()}\n";
Output:
now: 1352321491
date1 here: 1352321491
date1 Stockholm: 1352321491
I'm not sure if this is a bug or not, but it doesn't happen if you don't pick a date on which DST is changing.
Yes, unix timestamp is the current time as per the date object or your current machine time from Epoch.
Related
Short question but I can't get my finger on it. This piece of code:
$date = '2015-12-08T00:00:00+01:00';
echo date('D', strtotime($date));
returns Mon while
$date = '2015-12-08T00:00:00';
echo date('D', strtotime($date));
returns Tue. Why is that? The +01:00 is for the timezone, but that should not affect the day in my opinion.
First I've looked up that 08-12-2015 is in fact a Tuesday, so now we know the first one is incorrect.
PHP's date() is an Unix timestamp according to their own docs.
My belief is that adding the +1 as a timezone triggers the calculation to the +0 timezone (UTC) when asking for the day of the week and therefore returns 23:00 on monday as the current UTC time.
You can specify the timezone before executing the rest of the code: date_default_timezone_set('Europe/Amsterdam');
<?php
date_default_timezone_set('Europe/Amsterdam'); //this is an example of a +1 timezone, choose one from http://php.net/manual/en/timezones.php
$date = '2015-12-08T00:00:00+01:00';
echo date('D', strtotime($date) );
?>
strtotime will parse your date string using the supplied time zone or using the default timezone if unspecified. We can't see from the code you've posted what time zone your server is configured to, but once the date is parsed and converted to your time zone, the time may legitimately occur in the previous day, hence why you're seeing 'Mon'.
Either supply a time zone in the strtotime call via the now argument or set one globally with date_default_timezone_set.
So I have this code:
$timestamp = 1414708099;
echo $timestamp;
$date = date_make_date($timestamp, 'UTC', 'datestamp');
date_timezone_set($date, timezone_open('America/New_York'));
$timestamp = $date->format('U');
echo '<br>';
echo $timestamp;
which is supposed to convert the timezone of the initial timestamp from UTC to new york.
but then this ends up printing
1414708099<br>1414708099
hence the timezone didnt change...
what did I do wrong?
btw it also uses Drupal 6 date_api.module: http://drupalcontrib.org/api/drupal/contributions!date!date_api.module/function/date_make_date/6
As per comments
A timestamp is always UTC. You can't apply a time zone to a timestamp - consider its timezone as 0. Whatever you do, it stays 0. You asked for a date formatted with U - manual states this:
U: Seconds since the Unix Epoch (January 1 1970 00:00:00 GMT).
You can't get seconds from Unix Epoch for New York. That number is the same for any location in the world.
Now, had you formatted that date using, say, $date->format('Y-m-d H:i:s') then you would get correctly formatted time with the timezone offset for New York.
Long story short - there is no problem whatsoever here. It all works as intended.
I want to know how I could get the UTC time in year and months?
I've scraped the UTC date and time from a website, but I have been to asked to show the full UTC format such as (2014-07-31 22:00:00), the problem I'm facing now is that our current time is 1 hour ahead than UTC time.
Here's the code I'm using:
$date_time = date("Y-m", $time_now) . "-". $wxInfo['DAY'] . " " . $wxInfo['HOUR'] . ":" . $wxInfo['MINUTE'] . ":00";
As you can see, for the Y-m(year and month) I use local time, but the DAY, HOUR, MINUTE values from the website which is in UTC. This $date_time is updated every half hour, if they update on "2014-07-31 23:00:00", our current time is "2014-08-01 00:00:00". so my code will output:
2014-08-31 23:00:00
How can I convert to the right UTC year and month?
Use DateTime() with DateTimeZone()
// Set time to local time "now"
$datetime = new DateTime();
// Change timezone to UTC
$datetime->setTimeZone(new DateTimeZone('UTC'));
// Echo datetime in desired format
echo $datetime->format('Y-m');
The solution John Conde suggested works well for displaying dates and times in a specific timezone.
In your case, I think you may want to set the timezone to UTC on the whole script, so all your calls to date() and DateTime->format() automatically use UTC. That is really simple to do: at the beginning of your script, write:
date_default_timezone_set('UTC');
PHP will then use UTC as a timezone everywhere. See manual: http://php.net/date_default_timezone_set
I know this question has been answered many many times. I came in to a solution to solve this and its goes like this. I store all time stamps for each post in UTC on the server. Now i need to display the time stamp for a given timezone. I do this:
$tz : requested timezone
$ts : timstamp on db
$newts : new timestamp
$datetime = date('m/d/Y g:i a', $ts);
$dt = new DateTime($datetime, new DateTimeZone('UTC'));
date_default_timezone_set(trim($tz));
$newts = $dt->format('U');
date_default_timezone_set('UTC');
However the resulting time stamp is 60~ seconds higher than what is should be.
What am i doing wrong?
You're close, all you need to do is create the original DateTime object based on the timestamp/server timezone then set the new timezone and print the result, like so:
$datetime = new DateTime('#'.$ts, new DateTimeZone('UTC'));
$datetime->setTimezone(new DateTimeZone($tz));
print $datetime->format('m/d/Y g:i a');
The unix timestamp will be the same regardless of the timezone (it is TZ agnostic). The offset occurs when displaying it for different time zones. This is you can test this by printing the unix timestamp for each different timezone (they will be the same).
The U format gives you the number of "seconds since the Unix Epoch (January 1 1970 00:00:00 GMT)". That number does not depend on where on earth you are. So even if it might be 14:59 at your place while it's 10:24 at my place, the number of seconds since January 1 1970 00:00:00 GMT is the same at both our places. A "time stamp for a given timezone" does not make sense.
I am trying convert a utc time stored date to another time zone but i cant seem to get it right.
I have a time :
date1 = new DateTime('first day of the month');
date1.setTime(0,0,0); // Since using the first day of the month seems return the current time with different date
The default DateTime timezone is in UTC. The time i want to make reference is in 'Europe/Amsterdam' timezone. Any way i cant get the time in 'Europe/Amsterdam' timezone to be equivalent to the first day of the month time in UTC? (Uh, sorry my question was confusing.. let me just give an example to be clear). Im trying to query from a db.
If UTC date time is June 01, 2013. 00:00:00
I want to get get May 29, 2013 19:55:00.
I tried getting the difference between the two declared times with different timezones to get the time that i wanted but it seems it didnt work :(
My Edit/ Clarification:
If use this code:
$date1 = new DateTime('first day of the month');
$date1.setTime(0,0,0);
print_r($date1->format('Y-m-d H:i:s'));
I would get:
2013-06-01 00:00:00
Then if i use timezone:
$date1->setTimeZone(new DateTimeZone('Europe/Amsterdame'));
print_r($date1->format('Y-m-d H:i:s'));
I would get: (This is just a sample output):
2013-06-01 03:00:00
Because of time difference. Want i want to get is like the reverse: I want to get the datetime that when converted 'UTC' timezone i would get this: 06-01-2013 00:00:00 time. So my preffered output is : 2013-05-29 21:00:00 ...
You can do in an OOP way like so.
$date = new DateTime('2000-01-01 00:00:00', new DateTimeZone('Europe/Amsterdam'));
echo $date->format('Y-m-d H:i:s P') . "\n";
To set the default date in PHP, you can either set it in your ini file or in a PHP file like so:
date_default_timezone_set('Europe/Amsterdam');
Then to format the date, refer to http://www.php.net/manual/en/function.date.php for formatting.
In your case this would be:
date('j M Y' time());
Where j = day, M = month and Y = year.