I'm a bit stuck with the DateInterval class of PHP. What I really want is the number of seconds elapsed between two DateTime stamps.
$t1 = new DateTime( "20100101T1200" );
$t2 = new DateTime( "20100101T1201" );
// number of seconds between t1 and t2 should be 60
echo "difference in seconds: ".$t1->diff($t2)->format("%s");
Yet all I get is zero. Is the DateInterval class not suited for arithmetic? How can I get the 'exact' number of seconds (or hours, or whatever) between two time stamps?
If you just want the seconds quickly you might aswell use
$diff = abs($t1->getTimestamp() - $t2->getTimestamp());
Your code returns 0, because the actual seconds difference is 0, the difference in your example is 1 minute (1 minute, 0 seconds). If you print the %i format, you will get 1, which is the correct diff of $t1 and $t2.
Related
The following code will return the difference between two Carbon dates in minutes:
$carbonNow = Carbon::now();
$diff = $carbonNow->diffInMinutes($someRandomFutureDateVariable);
Which will return a single minute result. But I'm trying to get the difference in a 15 minute increments - such as every timestamp for every 15 minute increment in the result. Pseudo code would be:
[
'2020-10-15 12:45:00',
'2020-10-15 13:00:00',
'2020-10-15 13:15:00',
'2020-10-15 13:30:00',
...
]
In addition, I'd like to be able to set the time difference, so if I didn't want to target a 15 minute increment I could target whatever increment I pass into my function. I'm able to get the difference between two dates, but stuck on returning timestamps per each increment.
carbon::diffInMinutes delivers the minutes and removes the seconds.
The minute difference for a given minute increment can easily be calculated as follows:
$inc = 15; //15 minutes
$carbonNow = Carbon::now();
$diff = $carbonNow->diffInMinutes($someRandomFutureDateVariable);
$diffInc = $diff - $diff%$inc;
i am writing a time since function to return the time since a given mysql datetime. When taking the $oldtime from current time() it is returning a negative int when i need a positive int. I have written similar functions before in other languages but i have become blind to this problem, so any help would be much appreciated.
function timeSince($time){
$today = date("Y");
$oldtime = strtotime($time);
$time = time() - $oldtime;
$tokens = array (
3600 => 'h',
60 => 'm',
1 => 's'
);
if($time >= 86400){
}
}
echo timeSince('2016-02-25 14:35:00');
it could be much more convenient if you use PHP's DateTime and DateInterval classes and their methods:
function timeSince($datetime) {
$now = strtotime("now");
$then = strtotime($datetime);
$dt_now = new DateTime("#" . $now);
$dt_then = new DateTime("#" . $then);
//DateTime's diff method returns a DateInterval object which got a format method:
return $dt_now->diff($dt_then)->format('%a days, %h hours, %i minutes and %s seconds');
}
some test cases:
//my local date & time is around "2016-02-25 19:49:00" when testing
echo '<pre>';
echo timeSince('2016-02-25 19:30:00');
//0 days, 0 hours, 19 minutes and 11 seconds
echo PHP_EOL;
echo timeSince('2013-11-02 15:43:12');
//845 days, 4 hours, 4 minutes and 3 seconds
echo PHP_EOL;
echo timeSince('2017-01-31 00:22:45');
//340 days, 4 hours, 35 minutes and 30 seconds
echo PHP_EOL;
echo timeSince('1950-05-14 07:10:05');
//24028 days, 12 hours, 37 minutes and 10 seconds
echo PHP_EOL;
code partially based on this answer: https://stackoverflow.com/a/19680778/3391783
strtotime uses timezone in your PHP settings. Depending on timezone set, it might convert to the time that is yet to happen. For example, on my ukrainian server, strtotime('2016-02-25 14:35:00') converts to 1456403700, on a server in another timezone (US/Pacific) it converts to 1456439700.
Quote from PHP docs:
The function expects to be given a string containing an English date format and will try to parse that format into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 UTC), relative to the timestamp given in now, or the current time if now is not supplied.
Each parameter of this function uses the default time zone unless a time zone is specified in that parameter. Be careful not to use different time zones in each parameter unless that is intended. See date_default_timezone_get() on the various ways to define the default time zone.
You can add UTC/GMT offset to your datetime (1st param), for example strtotime('2016-02-25 14:35:00 +0800') or ('2016-02-25 14:35:00 GMT+08:00') will convert to 1456382100
In your example, $oldtime must be smaller value than current time().
So, if you want to count time between larger value, simply reverse your equation:
This line:
$time = time() - $oldtime;
Becomes:
$time = $oldtime - time();
I want to add an x number of week days (e.g. 48 weekday hours) to the current timestamp. I am trying to do this using the following
echo (strtotime('2 weekdays');
However, this doesn't seem to take me an exact 48 hours ahead in time. For example, inputting the current server time of Tuesday 18/03/2014 10:47 returns Thursday 20/03/2014 00:00. using the following function:
echo (strtotime('2 weekdays')-mktime())/86400;
It can tell that it's returning only 1.3 weekdays from now.
Why is it doing this? Are there any existing functions which allow an exact amount of weekday hours?
Given you want to preserve the weekdays functionality and not loose the hours, minutes and seconds, you could do this:
$now = new DateTime();
$hms = new DateInterval(
'PT'.$now->format('H').'H'.
$now->format('i').'M'.
$now->format('s').'S'.
);
$date = new DateTime('2 weekdays');
$date->add($hms);//add hours here again
The reason why weekday doesn't add the hours is because, if you add 1 weekday at any point in time on a monday, the next weekday has to be tuesday.
The hour simply does not matter. Say your date is 2014-01-02 12:12:12, and you want the next weekday, that day starts at 2014-01-03 00:00:00, so that's what you get.
My last solution works though, and here's how: I use the $now instance of DateTime, and its format method to construct a DateInterval format string, to be passed to the constructor. An interval format is quite easy: it starts with P, for period, then a digit and a char to indicate what that digit represents: 1Y for 1 Year, and 2D for 2 Days.
However, we're only interested in hours, minutes and seconds. Actual time, which is indicated using a T in the interval format string, hence we start the string with PT (Period Time).
Using the format specifiers H, i and s, we construct an interval format that in the case of 12:12:12 looks like this:
$hms = new DateInterval(
'PT12H12M12S'
);
Then, it's a simple matter of calling the DateTime::add method to add the hours, minutes and seconds to our date + weekdays:
$weekdays = new DateTime('6 weekdays');
$weekdays->add($hms);
echo $weekdays->format('Y-m-d H:i:s'), PHP_EOL;
And you're there.
Alternatively, you could just use the basic same trick to compute the actual day-difference between your initial date, and that date + x weekdays, and then add that diff to your initial date. It's the same basic principle, but instead of having to create a format like PTXHXMXS, a simple PXD will do.
Working example here
I'd urge you to use the DateInterface classes, as it is more flexible, allows for type-hinting to be used and makes dealing with dates just a whole lot easier for all of us. Besides, it's not too different from your current code:
$today = new DateTime;
$tomorrow = new DateTime('tomorrow');
$dayAfter = new DateTime('2 days');
In fact, it's a lot easier if you want to do frequent date manipulations on a single date:
$date = new DateTime();//or DateTime::createFromFormat('Y-m-d H:i:s', $dateString);
$diff = new DateInterval('P2D');//2 days
$date->add($diff);
echo $date->format('Y-m-d H:i:s'), PHP_EOL, 'is the date + 2 days', PHP_EOL;
$date->sub($diff);
echo $date->format('Y-m-d H:i:s'), PHP_EOL, 'was the original date, now restored';
Easy, once you've spent some time browsing through the docs
I think I have found a solution. It's primitive but after some quick testing it seems to work.
The function calculates the time passed since midnight of the current day, and adds it onto the date returned by strtotime. Since this could fall into a weekend day, I've checked and added an extra day or two accordingly.
function weekDays($days) {
$tstamp = (strtotime($days.' weekdays') + (time() - strtotime("today")));
if(date('D',$tstamp) == 'Sat') {
$tstamp = $tstamp + 86400*2;
}
elseif(date('D',$tstamp) == 'Sun') {
$tstamp = $tstamp + 86400;
}
return $tstamp;
}
Function strtotime('2 weekdays') seems to add 2 weekdays to the current date without the time.
If you want to add 48 hours why not adding 2*24*60*60 to mktime()?
echo(date('Y-m-d', mktime()+2*24*60*60));
The currently accepted solution works, but it will fail when you want to add weekdays to a timestamp that is not now. Here's a simpler snippet that will work for any given point in time:
$start = new DateTime('2021-09-29 15:12:10');
$start->add(date_interval_create_from_date_string('+ 3 weekdays'));
echo $start->format('Y-m-d H:i:s'); // 2021-10-04 15:12:10
Note that this will also work for a negative amount of weekdays:
$start = new DateTime('2021-09-29 15:12:10');
$start->add(date_interval_create_from_date_string('- 3 weekdays'));
echo $start->format('Y-m-d H:i:s'); // 2021-09-24 15:12:10
I'm trying to display the time x started, the time x finished, and how long x took to complete. I have the start and end displaying correctly, but the following subtraction gives me a bonkers answer.
// to unix timestamps for subtraction
$startTime = strtotime($row['bp_rec_start']);
$endTime = strtotime($row['bp_rec_end']);
$timeTaken = $endTime - $startTime;
//back to date formats
$startTime = date('H:i',$startTime);
$endTime = date('H:i',$endTime);
$timeTaken = date('H:i',$timeTaken);
e.g. ( 01:24 - 01:23 = 07:01)
Thanks
Timestamps are seconds since 1970, each timestamp representing an absolute point in time. So $endTime - $startTime produces some point in time like 1975-04-12 07:01:52. Printing the hour and minute part of that will of course print 07:01. The timestamp itself though is the difference in seconds, so you can do:
echo "Difference: $timeTaken seconds";
You should of course look into DateInterval (look at the 3rd example).
I am developing a quiz site and there is time for x min to answer the quiz. So when user clicks on start quiz link the starttime (current time at this instant) is recored in session. Also the endtime (start_time+ 30 min) is recorded in session and every time he submits a answer the current time is compared with the quiz end time. Only if the current time is less than end_time the answer should be accepted.
How can I get the currentdatetime?
How can I add x minutes to current this datetime?
How can I compare (<=) datetime ?
I think we should use date time. Is it right?
PHP measures time as seconds since Unix epoch (1st January 1970). This makes it really easy to work with, since everything just a single number.
To get the current time, use: time()
For basic maths like adding 30 minutes, just convert your interval into seconds and add:
time() + 30 * 60 // (30 * 60 ==> 30 minutes)
And since they're just numbers, just do regular old integer comparison:
$oldTime = $_SESSION['startTime'];
$now = time();
if ($now < $oldTime + 30 * 60) {
//expired
}
If you need to do more complicated things like finding the date of "next tuesday" or something, look at strtotime(), but you shouldn't need it in this case.
use php builtin functions to get time:
<?php
$currentTimeStamp = time(); // number of seconds since 1970, returns Integer value
$dateStringForASpecificSecond = date('Y-m-d H:i:s', $currentTimeStamp);
?>
for your application that needs to compare those times, using the timestamp is more appropriate.
<?php
$start = time();
$end = $start + (30 * 60); // 30 minutes
$_SESSION['end_time'] = $end;
?>
in the page where the quiz is submitted:
<?php
$now = time();
if ( $now <= $_SESSION['end_time'] ) {
// ok!
}
?>
Use the time() function to get a UNIX timestamp, which is really just a large integer.
The number returned by time() is the number of seconds since some date (like January 1, 1970), so to add $x minutes to it you do something like (time() + ($x*60)).
Since UNIX timestamps are just numbers, you can compare them with the usual comparison operators for numbers (< <= > >= ==)
time() will give you the current time in seconds since 1/1/1970 (an integer), which looks like it should be good.
To add x minutes, you'd just need to add x*60 to that, and you can compare it like any other two integers.
Source: http://us3.php.net/time
This is an old question but I wanted to provide an answer based on the PHP 5.2 DateTime class which I feel is much easier to use and much more versatile than any previous functions.
So how can i get the currentdatetime?
You can create a new DateTime object like this:
$currentTime = new DateTime();
But at this point, $currentTime is a datetime object and must be converted to a string in order to store it in a database or output it.
$currentTime = $currentTime->format('Y-m-d H:i:s');
echo $currentTime;
Outputs 2014-05-10 21:14:06
How can i add x minutes tocurrent this datetime?
You can add x minutes with the modify method:
$currentTime = new DateTime();
$addedMinutes = $currentTime->modify('+10 minutes');
echo $addedMinutes;
Outputs 2014-05-10 21:24:06
How can i comapare (<=) datetime ?
With the DateTime class, you can not only easily compare datetime objects, you can get the difference between them.
$currentTime = new DateTime('2014-05-10 21:14:06');
$addDays = $currentTime->modify('+10 days');
To compare
if ($currentTime >= $addDays) {
//do something//
}
$diffTime = new DateTime('2014-05-10 21:14:06');
$diff = $addDays->diff($diffTime);
$diff = $diff->format('There are %d days difference.');
echo $diff;
Outputs There are 10 days difference.