Uncaught exception 'Fuel\Core\PhpErrorException' ....system's timezone settings

Question

I Using Php 5.3, while changing from UTC To EDT/-4.0/DST Timezone it give the following errors. Please Help Me Out...Thanks.i will describe before and after timezone change errors...

BEFORE timezone CHANGE:

Fuel\Core\PhpErrorException [ Error ]: date_default_timezone_get() [function.date-default-timezone-get]: It is not safe to rely on the system's timezone settings. You are required to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/New_York' for 'EDT/-4.0/DST' instead

COREPATH/classes/fuel.php @ line 161

156            date_default_timezone_set(static::$timezone);
157        }
158        catch (\Exception $e)
159        {
160            date_default_timezone_set('UTC');
161            throw new \PHPErrorException($e->getMessage());
162        }
163
164        static::$encoding = \Config::get('encoding', static::$encoding);
165        MBSTRING and mb_internal_encoding(static::$encoding);
<br />

AFTER TIME ZONE CHAGE TO 'EDT/-4.0/DST'

Fatal error: Uncaught exception 'Fuel\Core\PhpErrorException' with message 'Unknown: It is not safe to rely on the system's timezone settings. You are required to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/New_York' for 'EDT/-4.0/DST' instead' in Unknown:0 Stack trace: #0 /home/files/website/bus/fuel/core/bootstrap.php(98): Fuel\Core\Error::error_handler(2, 'Unknown: It is ...', 'Unknown', 0) #1 [internal function]: {closure}(2, 'Unknown: It is ...', 'Unknown', 0, Array) #2 {main}

thrown in Unknown on line 0

Warning: file(Unknown) [function.file]: failed to open stream: No such file or directory in /home/files/website/bus/fuel/core/classes/debug.php on line 325

Warning: array_unshift() expects parameter 1 to be array, boolean given in /home/files/website/bus/fuel/core/classes/debug.php on line 326

Warning: array_slice() expects parameter 1 to be array, boolean given in /home/files/website/bus/fuel/core/classes/debug.php on line 341

Backtrace COREPATH/bootstrap.php @ line 66

61            \Cli::error("Error: ".$e->getMessage()." in ".$e->getFile()." on ".$e->getLine());
62            \Cli::beep();
63            exit(1);
64        }
65    }
66    return \Error::shutdown_handler();
67});
68
69set_exception_handler(function (\Exception $e)
70{
71    // reset the autoloader