Fix Float formatting

Author: p

source/tutorials/mongoid-documents.txt

@@ -333,7 +333,7 @@ Mongoid allows assignment of values of several types to ``Date`` fields:
 - ``Time``, ``DateTime``, ``ActiveSupport::TimeWithZone`` - the date component
   of the value is taken in the value's time zone.
 - ``String`` - the date specified in the string is used.
-- ``Integer``, ''Float`` - the value is taken to be a UTC timestamp which is
+- ``Integer``, ``Float`` - the value is taken to be a UTC timestamp which is
   converted to the :ref:`configured time zone <time-zones>` (note that
   ``Mongoid.use_utc`` has no effect on this conversion), then the date is
   taken from the resulting time.