begin translating "TimeHelper"

ja/core-libraries/helpers/time.rst

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+TimeHelper
+##########
+
+.. php:class:: TimeHelper(View $view, array $settings = array())
+
+The Time Helper does what it says on the tin: saves you time. It
+allows for the quick processing of time related information. The
+Time Helper has two main tasks that it can perform:
+
+#. It can format time strings.
+#. It can test time (but cannot bend time, sorry).
+
+.. versionchanged:: 2.1
+   ``TimeHelper`` have been refactored into :php:class:`CakeTime` class to allow
+   easier use outside of the ``View`` layer.
+   Within a view, these methods are accessible via the `TimeHelper`
+   class and you can called it as you would call a normal helper method:
+   ``$this->Time->method($args);``.
+
+Using the Helper
+================
+
+A common use of the Time Helper is to offset the date and time to match a
+user's time zone. Lets use a forum as an example. Your forum has many users who
+may post messages at any time from any part of the world. An easy way to
+manage the time is to save all dates and times as GMT+0 or UTC. Uncomment the
+line ``date_default_timezone_set('UTC');`` in ``app/Config/core.php`` to ensure
+your application's time zone is set to GMT+0.
+
+Next add a time zone field to your users table and make the necessary
+modifications to allow your users to set their time zone. Now that we know
+the time zone of the logged in user we can correct the date and time on our
+posts using the Time Helper::
+
+    echo $this->Time->format('F jS, Y h:i A', $post['Post']['created'], null, $user['User']['time_zone']);
+    // Will display August 22nd, 2011 11:53 PM for a user in GMT+0
+    // August 22nd, 2011 03:53 PM for a user in GMT-8
+    // and August 23rd, 2011 09:53 AM GMT+10
+
+Most of the Time Helper methods have a $timezone parameter. The $timezone parameter
+accepts a valid timezone identifier string or an instance of `DateTimeZone` class.
+
+.. include:: ../../core-utility-libraries/time.rst
+    :start-after: start-caketime
+    :end-before: end-caketime
+
+.. meta::
+    :title lang=en: TimeHelper
+    :description lang=en: The Time Helper will help you format time and test time.
+    :keywords lang=en: time helper,format time,timezone,unix epoch,time strings,time zone offset,utc,gmt