diff --git a/lib/time_utils.rb b/lib/time_utils.rb
index c1c0d07e..0af5a928 100644
--- a/lib/time_utils.rb
+++ b/lib/time_utils.rb
@@ -22,7 +22,7 @@ module TimeUtils
   DEFAULT_DATE_FORMAT_US = 'MM/DD/YYYY'
   DEFAULT_DATE_FORMAT = 'DD/MM/YYYY'
 
-  US_TIMEZONES = %w[EST CST MST PST HST AKDT].freeze
+  US_TIMEZONES = %w[EST EDT CST CDT MST MDT PST PDT HST HDT AKST AKDT].freeze
 
   module_function