Fix spelling, grammar, usage, and markup.

Doc/lib/libtime.tex

@@ -295,10 +295,11 @@ string to be parsed has excess data after parsing,
 any missing data is \code{(1900, 1, 1, 0, 0, 0, 0, 1, -1)} .
 
 Support for the \code{\%Z} directive is based on the values contained in
-\code{tzname} and whether \code{daylight} is true.  Because of this
-it is platform-specifc sans recognition for UTC and GMT which are
+\code{tzname} and whether \code{daylight} is true.  Because of this,
+it is platform-specific without recognition for UTC and GMT which are
 always known (and are considered to be non-daylight savings
 timezones).
+\end{funcdesc}
 
 \begin{datadesc}{struct_time}
 The type of the time value sequence returned by \function{gmtime()},