docs: add user guide

Author: kenjis

user_guide_src/source/changelogs/v4.3.0.rst

@@ -70,6 +70,7 @@ Others
 - Added new Form helper function :php:func:`validation_errors()`, :php:func:`validation_list_errors()` and :php:func:`validation_show_error()` to display Validation Errors.
 - Now you can autoload helpers by **app/Config/Autoload.php**.
 - ``BaseConnection::escape()`` now excludes the ``RawSql`` data type. This allows passing SQL strings into data.
+- Added :ref:`Time::toDatabase() <time-todatabase>` to get a datetime string that can be used with databases regardless of locale.
 
 Changes
 *******

user_guide_src/source/libraries/time.rst

@@ -171,6 +171,17 @@ Displays just the localized version of time portion of the value:
 
 .. literalinclude:: time/018.php
 
+.. _time-todatabase:
+
+toDatabase()
+============
+
+.. versionadded:: 4.3.0
+
+This method returns a string that can be used with databases regardless of locale.
+
+.. literalinclude:: time/042.php
+
 humanize()
 ==========
 

user_guide_src/source/libraries/time/042.php

@@ -0,0 +1,9 @@
+<?php
+
+// Locale: en
+$time = Time::parse('March 9, 2016 12:00:00', 'America/Chicago');
+echo $time->toDatabase(); // '2016-03-09 12:00:00'
+
+// Locale: fa
+$time = Time::parse('March 9, 2016 12:00:00', 'America/Chicago');
+echo $time->toDatabase(); // '2016-03-09 12:00:00'