ServerDate synchronizes with the server's clock in the browser.
Clone or download
NodeGuy Merge pull request #33 from hq9000/anti-caching-changes
changes in url genration algorithm for iterative server probing.
Latest commit 65f6042 Jul 24, 2017
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
Example Changed example to work without PHP or Node. Sep 25, 2015
lib restoring blank lines in header Jul 24, 2017
test Run tests using Selenium within Docker. Feb 24, 2016
.gitignore Add node_modules to .gitignore. Jan 22, 2014
LICENSE first commit Aug 14, 2012
LICENSE.LESSER first commit Aug 14, 2012
README.md Fix typo in references. Oct 17, 2016
package.json Run tests using Selenium within Docker. Feb 24, 2016

README.md

Introduction

ServerDate is used in web pages to make the server's clock available to the client's browser via Javascript.

You can use it when you want to display the current time but don't trust the browser's clock to be accurate, or to synchronize events for different users of your web site by synching them all to the server's clock.

Usage is simple. Add one <SCRIPT> element to your web page and then you can use the ServerDate object in Javascript just like you use the built-in Date object, except that it reflects the server's time instead of the client's.

Requirements

ServerDate has been tested in the following browsers:

  • Chrome 23.0.1271.64
  • Firefox 16.0.2
  • Safari 6.0.1 (7536.26.14)
  • Internet Explorer 11.0.9600.18015

Installation

Include the following <SCRIPT> element in your web page:

<SCRIPT src="ServerDate.js"></SCRIPT>

Usage

You may then use ServerDate as you would use the Date object or one of its instances, e.g.:

> ServerDate()
"Mon Aug 13 2012 20:26:34 GMT-0300 (ART)"

> ServerDate.now()
1344900478753

> ServerDate.getMilliseconds()
22

There is also a new method to get the precision of ServerDate's estimate of the server's clock (in milliseconds):

> ServerDate.toLocaleString() + " ± " + ServerDate.getPrecision() + " ms"
"Tue Aug 14 01:01:49 2012 ± 108 ms"

You can see the difference between the server's clock and the browsers clock, in milliseconds:

> ServerDate - new Date()
39

There is no constructor because it doesn't make sense to create more than one instance of ServerDate.

Methods from Date to change the time, such as setMinutes, are not defined:

> ServerDate.setMinutes
undefined

ServerDate is synchronized with the server's clock when it is first loaded and then re-synchronizes itself from time to time to keep the two clocks from drifting apart.

References

Copyright

Copyright 2012 David Braun

This file is part of ServerDate.

ServerDate is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

ServerDate is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with ServerDate. If not, see http://www.gnu.org/licenses/.