Time Sync() PHP and Javascript

Question

if I generate a time() on the PC purchased in Brazil it will result a team according to our time and such, if I repeat the process in China, USA or any other place with a local PC or time() will be different. My doubts are:

How to define that the team() results the US team() for example?

How to define my tipo time() by javascript for it to send to PHP and adapt the team()?

Type I’m accessing a server where the time() refers to the time Brazil, but my team() refers to the US and I want to warn the server (through Javascript) my type of team to synchronize with my time.. you understand that?

Answer 1

It looks like you’re getting trouble where you don’t have it. According to the documentation, the function time of PHP:

Returns the current time measured in the number of seconds since the Unix Era (January 1 1970 00:00:00 GMT).

And for the Javascript, Date.prototype.getTime() works the same (but in milliseconds instead of seconds):

The value returned by the getTime() method is the number of milliseconds Since 1 January 1970 00:00:00 UTC.

The two functions already work in sync. Therefore:

// Em JS:
var agora = new Date().getTime();

// Em PHP:
$agora = time() * 1000;
// Ou, com mais precisão:
// $agora = microtime(true) * 1000;

Answer 2

To return which is the current Timezone, you can use the getTimezoneOffset.

var timezoneoffset = new Date().getTimezoneOffset();

This will return the difference in minutes of local time and UTC time (0:00).

These minutes also consider daylight saving time.

Instead of using this, I suggest you use UTC in the backend and frontend,

Javascript is supported to take your local date and time and convert to Timezone UTC, for example:

For example,

var timestamp = new Date().getTime();

Will return a timestamp based on time zone UTC (0:00)

var d = new Date(1429016291946);

or

var d = new Date();
d.setTime(1429016291946);

It will mount a date from the timestamp. I put the two forms because I did not find documentation on the first, although it works.

In PHP, the function time returns a timestamp in time zone 0:00.

Javascript works with timestamp in milliseconds and PHP with seconds, at some point in your code you will have to truncate the value or multiply by 1000, normalizing for javascript or PHP.

References

• https://stackoverflow.com/questions/8655515/get-utc-time-in-php
• https://stackoverflow.com/questions/8047616/get-a-utc-timestamp-in-javascript
• http://www.w3schools.com/jsref/jsref_gettimezoneoffset.asp
• http://www.w3schools.com/jsref/jsref_obj_date.asp
• http://www.w3schools.com/jsref/jsref_settime.asp

Answer 3

I believe the function you seek is date_default_timezone_set

Example of use:

date_default_timezone_set('America/Sao_Paulo');

At this link, you find the supported Timezones.

Read more about, in the documentation.

Hug

Answer 4

Not much code required.

In fact, with a line you can solve the problem at once:

var time=new Date(<?=gmmktime()?>000) //Equivalente a <?php echo gmmktime();?>
var time=new Date(<?=gmdate('t')?>000) //Produz o mesmo resultado

The 000 is necessary because PHP returns time in seconds, while Javascript waits for time in milliseconds. Adding 000 at the end of the number (or multiply by 1000) solves the difference.

To get the time, based on server time, without having a setInterval();, some amendments are needed:

var time=new Date(<?=gmmktime()?>000); //hora do servidor
var time_dif=(new Date())-time; //subtrai a diferença em milisegundos em relação às duas datas

/* [... algum tempo depois ...] */

var server_time=new Date(); //cria uma nova data
server_time.setTime(server_time-time_diff); //subtrai a diferença

It doesn’t take much more than this.