Let's say I have a table and it consists a column of next_update (which is in a date format), time_left (which is in the unit of days). How could I program it for example the next_update is 27/02/14 and the time_left is 3 days for today(24/02/14) view in a php webpage but for tomorrow view in the php page will be automatically deducted to 2 days. I'm using postgresql as my database and php as the web interface. The main problem now is how can I make the value of time_left be minus by the next_update with the current date.
I've gone through some basic manual but still have no idea to set this up. Sincerely thank you all for any help.
Try this code
<?php
$now = time();
$next_update = strtotime("2014-02-27");
$datedifferent = $next_update - $now;
$days = floor($datedifferent/(60*60*24));
if($days > 0) {
echo $days.' more days you have';
}
?>
SELECT next_update, next_update - now() as time_left FROM <your_table>
You may also want to apply function EXTRACT to subtract necessary time units from interval (documentation)
Related
I'm wanting to display on a php page the difference between the current server time and a datetime row plus a row that has milliseconds in it, so I guess the equation would look kind of like ((Datetime+Milliseconds)-Server Time).
The only problem is, I'm not sure how to do it in code. I can currently get the difference between the datetime row and the current time with echo strtotime($row['date_added']) - time(); When I try adding the row that contains the milliseconds, date_mil, I get a really long number.
The date in the row date_added looks like 2012-05-25 16:55:06 and the value of the date_mil is around 218238.
I'm still learning how to do all of this, and this has me confused. Thanks for the help!
I just solved my own problem.
$difference = time() - strtotime($row['date_added']);
$milliseconds = round(($row['date_mil']) * .001);
echo $milliseconds - $difference;
We have a battle system where people can pick a match time to challenge another player. To create a match the user needs to pick a date. Currently a user picks the day, hour, minute, and pm/am from a dropdown list. If the user selects 5/20/2012 # 1PM, the system adds the hours and minutes from the start of the day. Here's a quick sample to get a better understanding of what I'm talking about:
$time = strtotime('today', $inputdate);
$time = $time + $hours + $minutes;
the value of $hours changes if the users selects AM or PM. It's pretty basic:
Everything was working fine until people started have timezone issues. For example, if player A creates a match at 1:PM, then player B will see the match starts at 1:PM, but he/she will have different timezones!
The problem is that I don't know the problem :/
I don't know how to fix the timezone issue. I have been creating functions in the hopes that everything will fall together, but no luck.
What I have:
User profiles have a timezone options.
A function that gets the raw timestamp and returns the formatted time based on the user's timezone.
A function that gets a timestamp and converts it to another timestamp
based on the user's timezone.
I'm lost and I can't seem to fix the issue, I can code, but right now I'm not thinking logical. I took me one hour to write this and try to explain it how I could, since I myself don't know how to make it work. Some advice is appreciated.
I need a function to convert a timestamp to UTC-5:
function input_date($timestamp)
{
global $vbulletin;
$timestamp = (int)$timestamp;
if (strlen((string)$timestamp) == 10)
{
$hour = 3600.00;
$offset = $vbulletin->userinfo['timezoneoffset'];//sample -8
$ds = (int)$vbulletin->userinfo['dstonoff'];//DST
$fluff = $hour*($offset+5.00);
$timestamp = $timestamp+$fluff+($ds*$hour);
return $timestamp;//return timestamp in UTC-5 format..
}
else
{
return 0;
}
}
Essentially everything in the database should be stored using a single timezone, preferably one which is not affected by DST. The standard option here is UTC.
If you know the user's timezone by its name, you can use that to generate your time:
// Player A creates match at 1PM Europe/London
$timezone = 'Europe/London';
$localTime = '2012-03-01 13:00:00';
// work out UNIX timestamp using that timezone (making it timezone independent)
date_default_timezone_set($timezone);
$timestamp = strtotime($localTime);
// store $timestamp in the database
// Player B views the timestamp with timezone America/Los_Angeles
$timezone = 'America/Los_Angeles';
date_default_timezone_set($timezone);
var_dump(date('c', $timestamp)); // see manual for more output formats
If you have the timezones stored as their abbreviations (e.g. "CET", "GMT"), then use timezone_name_from_abbr to get the correct timezone name.
I need to compare two dates to show an edit link if it is within 5 mins after the post was made, in PHP. If more than 5 minutes have passed, don't show anything.
$answer_post_date = get_the_time("Y-m-d");
$current_date = date("Y-m-d");
$formated_current_date = strtotime($answer_post_date);
$formated_answer_post_date = strtotime($current_date);
At this point I have two values:
1274414400 ($formated_current_date)
1276056000 ($formated_answer_post_date)
I am not sure what to do next to check if the current date/time is > 5 mins from the answer post date.
Any suggestions would be great.
All I really need the answer to be is a Boolean (yes/no) and if yes, display the minuets left to show the link to edit.
You're only handling dates, how are you supposed to know if the difference is 5 minutes?
Anyway, I'd say the majority of the PHP code that uses the default PHP functions is at least somewhat broken. The problem is you, despite a unix timestamp storing the correct point in time something happens, it does not store timezone information. See here.
So, forget using only date and strtotime. Use the datetime extension.
Store in the database the Unix timestamp and the timezone (by timezone I mean e.g. Europe/Lisbon). Then:
$tz = new DateTimeZone($timezone);
$answer_post_date = new DateTime("$timestamp");
$answer_post_date->setTimeZone($tz);
$current_date = new DateTime("now", $tz);
$diff = $current_date->diff($answer_post_date);
if ($diff->format("a") > 0 ||
$diff->format("h") > 0 ||
$diff->format("m") >= 5) {
//more than 5 minutes have passed
}
Of course, for comparing dates, you can always compare the timestamps.
My understanding of what you need to do:
$delta = ($formated_current_date - $formated_answer_post_date) / 60; // in minutes
if ($delta < 5) {
// show $delta
}
EDIT: Like others pointed out, this alone will not fix all of the issues at hand. As I see it, the smallest change to your current code would be to use a date format with higher granularity - such as "Y-m-d H:i:s". This being enough, like others pointed out, is contingent on the post's date being in the same timezone as your system.
I don't see the need to do a round-trip to a string format and back, regardless of how efficient or reliable it is.
date() will default to calling time() which you can call directly and get the current time in seconds as a Unix epoch timestamp (which is what you're trying to end up with in $formated_answer_post_date). You need to look in the WordPress docs to find the equivalent based on the post's value.
Then you can do a simple comparison of seconds. 5 minutes is 300 seconds.
You will still need to check that the code can assume the timezones of both values will be the same.
Hi guys I was wondering if anyone could help me with the following:
I have two dates entered in two different fields > startDate and endDate.
As they are entered I would like to show a warning if:
the second one is a date before the first one. So it is wrong.
and that between the first one and the second one there a minimum gap of at least 3 days during certain period of the year and 7 days during other periods of the year.
I was thinking to write a PHP function but how do I call it as soon as the second date is entered?
Many many thank for you help
Francesco
Convert your dates to Julian day with gregoriantojd.
/**
* Get the Julian day of a date. The Julian day is the number of days since
* January 1, 4713 BC.
*/
function datetojd($date)
{
return gregoriantojd(idate('m', $date),
idate('d', $date),
idate('Y', $date));
}
// you can use strtotime to parse a lot of date formats, assuming they are text
$startDate = strtotime('22nd Nov 2009');
$finishDate = strtotime('26nd Nov 2009');
$diff = datetojd($finishDate) - datetojd($startDate);
if ($diff < 0) {
// oops, $finishDate is before $startDate
}
else {
// check $diff is at least 3 or 7 depending on the dates
}
Do the check on the client side with Javascript.
Then perform the same checks server side which can present a message after the form has been submitted (for those few users running with Javascript disabled?).
I'm not sure if you can call it as soon as the second date is entered, unless you reload the page or have the function on another page which could get a tad complicated
The way i would check the dates is to use php's mktime function, which will give you the unix time. Then if the second one is less that the first, the second date is before and if the second one is less that the first + 3 * 24 *60 * 60 (seconds in 3 days) then it isn't 3 days apart
1° case:
SELECT [whatever you need from the table] WHERE endDate < startDate
2°case:
SELECT [whatever you need from the table] WHERE (endDate - startDate) >= IF([select that define in wich period of the year the data are],3, 7)
This ill do the trick, but probably your problem cant be solved sql-side.
Please, describe better what you need to do.
EDIT:
Ok, then as someone else suggested, first check htem by js (for convenience, not for safely: never rely only on js validation!)
Use strtotime for the comparison/operation.
EDIT2 (last;) :
Go with Alex's Answer
I have a site that stores a bunch of records in an sql database that i want to pull onto a page based on the date, which is stored as Y-m-d in sql. But, I want to paginate the results based on day.
So for the index, i want to show all the results from the current day, for which i was going to use the php date() function as the WHERE in my QUERY. But I'm hitting a snag on doing the pagination. I want to have buttons at the bottom that go to the next page with a get, so index.php?page=2 would be tomorrow, but i cant figure out how to select "tomorrow" reliably from the database in my WHERE.
See, i was going to use date("U") to get the unix time in seconds of the first day on the first page and then just add 3600*$_GET['page'] for incrementing the date on the next pages, but that seems like a sloppy way to do it that might wind up messing me up. Is this the only way or is there a better, more practical solution - thanks a lot guys I appreciate it.
If page 2 is tomorrow, then you're going to be looking at something like this:
$days_ahead = $page - 1;
$query = "... WHERE date = DATE(NOW()) + INTERVAL $days_ahead DAY ...";
Note that this would work fine on the first page too (assuming $page gets defaulted to 1), it'd add 0 days to today's date.
You experiment with strtotime:
$sqldate = date('Y-m-d', strtotime('+2 days'));
This is how I managed to fix it for my site
//'page' is a GET variable from url
if($page<=1) {
$datemax = time();
$datemin = time() - (1 * 2592000); //2592000 being seconds in a month
}
else{
$datemax = time() - (($page - 1) * 2592000);
$datemin = time() - ($page * 2592000);
}
And then obviously the query will look something like
SELECT * FROM posts WHERE dateposted >=$datemin AND dateposted <=$datemax