I am new to PHP and am writing a PHP script that contains a module which reads the file timestamp out of a file and then compare with system time to see whether the file is older than 5 minutes or not and I am wondering how that can be achieved. I am currently using
$timeStamp = strftime('%c', filectime($this->localPath));
$timeStamp2 = filectime($this->localPath);
The two $timeStamp and $timeStamp2 are different, the 1st one is more human readable
$timeStamp Mon Jun 20 15:17:01 2011
$timeStamp2 1308608221
What does $timeStamp2 mean?
And again, how to see if the file is more than 5 minutes old?
That is Unix timestamp actually (seconds since 1st jan 1970 or EPOCH)
You can use time() function to get current time in same Unix format.
And then subtract both time values to check whether difference is > 300 (5 min) or not.
$timeStamp2 is a UNIX timestamp (the number of seconds passed since 01/01/1970).
You can get the same thing from $timeStamp1 by doing
$timeStamp1 = strtotime($timeStamp1)
and then compare the two values
Answering your question "What does $timeStamp2 mean?"
1308608221 is the number of seconds that have passed since midnight January 1,1970.
Related
If I got a unix time which is e.g
1407050129
How do I get the 12:00AM of that unix day in unix timestamp , means the first minute of the day of that unix time.
Example if i want get today first minute
$today_first_min = strtotime("00:00:00");
Try this:
$that_day = "1407050129";
$that_day_first_min = strtotime(date('Y-m-d', $that_day) . ' midnight');
See demo
An alternate method to arrive at the same result... Unix time is a count of seconds since 1970-01-01 00:00:00 UTC, so each whole day is a multiple of (60*60*24) seconds.
Using this fact you can use the modulus operator (%) to calculate and then remove the remainder (ie. the seconds, hours and minutes) from the day, and get back to the first hours!
date_default_timezone_set('UTC');
$that_date = 1407050129;
$first_hour = $that_date - ($that_date % (60*60*24));
print date('Y-m-d H:i:s', strval($first_hour));
// 2014-08-03 00:00:00
I want to calculate difference of two times and print it in pretty way. I know the difference will never exceed 24 hours, so I tried the following
$time = 7200; //time difference in seconds
date("H:i:s", $time); // should print 02:00
The result is unexpected, it prints 03:00 instead.
What am I doing wrong?
Why not the DateTime::diff??
Here, check PHP.net for DateTime class
Grabbed from php.net datetime diff page:
$datetime1 = new DateTime('2009-10-11');
$datetime2 = new DateTime('2009-10-13');
$interval = $datetime1->diff($datetime2);
echo $interval->format('%R%a days');
//Outputs +2 days
The PHP date() function is meant for formatting absolute time stamps (as in "Friday, 20 July 2012, 15:02 UTC"), not for time differences (as in "3 hours and 5 minutes ago").
In some cases, it is possible to trick date() into producing something that looks like a correctly formatted time difference by setting your time zone to UTC and relying on the fact that the Unix epoch happens to fall on midnight in UTC. However, even then, this will only work for positive time differences of less than 24 hours.
Instead, the correct solution is to use a function designed for formatting time differences, or write one yourself. Here's a simple function to do so:
function format_time_difference ( $delta ) {
$sign = ( $delta < 0 ? "-" : "" );
$delta = abs( $delta );
return sprintf( "%s%02d:%02d:%02d", $sign, $delta / 3600,
($delta / 60) % 60, $delta % 60 );
}
Of course, you can extend this function to e.g. include days in the output if you like.
You should never use date to compute time difference. Firstly it is ugly hack. It was not intended for that purpose. And secondly, it works reliably only when timezone set to UTC.
Now, why it does not work:
PHP function date takes two arguments, format and timestamp, the latter is defined as number of seconds from 1st January 1970 00:00 UTC called unix epoch. So if you call date("H:i", 3600) and your timezone is set to UTC, it will return "01:00", cause it represents time one hour after unix epoch and the epoch was at the midnight.
The problem is, unix epoch was at the midnight only in UTC, not in the other timezones. And this is the source of the incorrect result.
I download event calender from http://www.phpcodeworks.com/pec/installation. I am using PHP 5.3.X therefore browser said F:\xampp\htdocs\msj\functions.php so I replace :
$days = date("t", mktime(0,0,0,$month,1,$year));
with:
$days = date("t",` time(0,0,0,$month,1,$year));
but doing so each date goes 24 hours back as follows.
Image when using $days = date("t", mktime(0,0,0,$month,1,$year));:
Image when using $days = date("t", time(0,0,0,$month,1,$year));:
The mktime() function returns the time in seconds from Unix Epoch (January 1 1970 00:00:00 GMT) to the date and time provided as parameters.
The time() function retuns the time in seconds from Unix Epoch (January 1 1970 00:00:00 GMT) to the moment the function is run. There are no parameters to pass in.
So when browsing for a particular date, you will need to use mktime() instead of time(), time() will constantly return a different number every time you run it. Because of that, your calendar will change every time you view it (even if you are trying to view a particular date).
Hightlight:
mktime() - Time in seconds representing a specified date (see the documentation for the required parameters).
time() - Time in seconds representing now (there are no parameters for this function).
mktime() looks to be the appropriate function for this situation.
i have to sent an email when a user register email contain a link that is become invalid after six hours
what i m doing when email is sent i update the db with field emailSentDate of type "datetime"
now i got the curent date and time and has made to the same formate as it is in db now i want to find that both these dates and time have differenc of 6 hours or not so that i can make link invalid but i donot know how to do this
my code is look like this i m using hardcoded value for db just for example
$current_date_time=date("Y-m-d h:i:s");
$current=explode(" ",$current_date_time);
$current_date=$current[0];
$current_time=$current[1];
$db_date_time="2010-07-30 13:11:50";
$db=explode(" ",$db_date_time);
$db_date=$db[0];
$db_time=$db[1];
i do not know how to proceed plz help
<?php
//$now = new DateTime(); // current date/time
$now = new DateTime("2010-07-28 01:11:50");
$ref = new DateTime("2010-07-30 05:56:40");
$diff = $now->diff($ref);
printf('%d days, %d hours, %d minutes', $diff->d, $diff->h, $diff->i);
prints 2 days, 4 hours, 44 minutes
see http://docs.php.net/datetime.diff
edit: But you could also shift the problem more to the database side, e.g. by storing the expiration date/time in the table and then do a query like
... WHERE key='7gedufgweufg' AND expires<Now()
Many rdbms have reasonable/good support for date/time arithmetic.
What you can do is convert both of your dates to Unix epoch times, that is, the equivalent number of seconds since midnight on the 31st of December 1969. From that you can easily deduce the amount of time elapsed between the two dates. To do this you can either use mktime() or strtotime()
All the best.
$hoursDiff = ( time() - strtotime("2010-07-30 13:11:50") )/(60 * 60);
I'd rather work with a timestamp: Save the value which is returned by "time()" as "savedTime" to your database (that's a timestamp in seconds). Subtract that number from "time()" when you check for your six hours.
if ((time() - savedTime) > 6 * 3600)
// more than 6h ago
or
"SELECT FROM table WHERE savedTime < " . (time() - 6 * 3600)
This might be the solution to your problem -> How to calculate the difference between two dates using PHP?
How would I construct a statement like if current time ($time) is more than 30 seconds past time ($djs['currenttime'])? Would it be something like
if ($time => $djs['currenttime'])? I can't figure it out with the 30 seconds..:).
Thanks :).
The 30 seconds you are struggling with it's simply a +30 added on the conditional incrementing the value of $djs['currenttime'].
You can use the time() function to get the actual time. I'm assuming that djs['currenttime'] is a value extracted from the database. Therefore the comparison would be the following:
if(time() > $djs['currenttime'] + 30){
//actions here;
}
time() returns the number of seconds since Jan 1st 1970 00:00:00 GMT so for this to work, the format of the $djs['currenttime'] variable should also be a unix timestamp. If not, you will need to convert one of them to the appropriate format first.
if ($time > ($djs['currenttime'] + 30))
Assumes that both values are actual timestamps and not formatted strings