TimeZone getting Fatal Error

All of a sudden I’m getting a fatal error under settings for timezone –
Warning: timezone_open() [function.timezone-open]: Unknown or bad timezone (Etc/UTC-4) in /public_html/wp-includes/functions.php on line 3325
Local time is 2010-01-26 20:14:20
Choose a city in the same timezone as you.
This timezone is currently in standard time.

Fatal error: Uncaught exception ‘Exception’ with message ‘DateTimeZone::__construct() [datetimezone.–construct]: Unknown or bad timezone (Etc/UTC-4)’ in /public_html/wp-admin/options-general.php:184 Stack trace: #0 /public_html/wp-admin/options-general.php(184): DateTimeZone->__construct(‘Etc/UTC-4’) #1 {main} thrown in /public_html/wp-admin/options-general.php on line 184

Please is there a work around or fix?

thanks