`:datetime` and `:time` columns allows `:precision` option [ci skip]

activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb

@@ -518,14 +518,15 @@ def drop_table(table_name, options = {})
       # Available options are (none of these exists by default):
       # * <tt>:limit</tt> -
       #   Requests a maximum column length. This is the number of characters for a <tt>:string</tt> column
-      #   and number of bytes for <tt>:text</tt>, <tt>:binary</tt> and <tt>:integer</tt> columns.
+      #   and number of bytes for <tt>:text</tt>, <tt>:binary</tt>, and <tt>:integer</tt> columns.
       #   This option is ignored by some backends.
       # * <tt>:default</tt> -
       #   The column's default value. Use +nil+ for +NULL+.
       # * <tt>:null</tt> -
       #   Allows or disallows +NULL+ values in the column.
       # * <tt>:precision</tt> -
-      #   Specifies the precision for the <tt>:decimal</tt> and <tt>:numeric</tt> columns.
+      #   Specifies the precision for the <tt>:decimal</tt>, <tt>:numeric</tt>,
+      #   <tt>:datetime</tt>, and <tt>:time</tt> columns.
       # * <tt>:scale</tt> -
       #   Specifies the scale for the <tt>:decimal</tt> and <tt>:numeric</tt> columns.
       # * <tt>:collation</tt> -