diff --git a/actionview/lib/action_view/helpers/date_helper.rb b/actionview/lib/action_view/helpers/date_helper.rb
index 4b4f0ae577..46ce7cf0be 100644
--- a/actionview/lib/action_view/helpers/date_helper.rb
+++ b/actionview/lib/action_view/helpers/date_helper.rb
@@ -177,6 +177,8 @@ module ActionView
       #   and +:name+ (string). A format string would be something like "%{name} (%<number>02d)" for example.
       #   See <tt>Kernel.sprintf</tt> for documentation on format sequences.
       # * <tt>:date_separator</tt>    - Specifies a string to separate the date fields. Default is "" (i.e. nothing).
+      # * <tt>:time_separator</tt>    - Specifies a string to separate the time fields. Default is "" (i.e. nothing).
+      # * <tt>:datetime_separator</tt>- Specifies a string to separate the date and time fields. Default is "" (i.e. nothing).
       # * <tt>:start_year</tt>        - Set the start year for the year select. Default is <tt>Date.today.year - 5</tt> if
       #   you are creating new record. While editing existing record, <tt>:start_year</tt> defaults to
       #   the current selected year minus 5.