Document chrono

doc/api.rst

@@ -421,15 +421,15 @@ For example::
     fmt::print("strftime-like format: {:%H:%M:%S}\n", 3h + 15min + 30s);
   }
 
-prints::
+prints:
 
-  Default format: 42s 100ms
-  strftime-like format: 03:15:30
+.. code:: none
+
+   Default format: 42s 100ms
+   strftime-like format: 03:15:30
 
 Chrono format specifications are described in :ref:`chrono-specs`.
 
-.. doxygenclass:: formatter<std::chrono::time_point<std::chrono::system_clock>, Char>
-
 .. _compile-api:
 
 Format string compilation

doc/syntax.rst

@@ -319,13 +319,15 @@ Format specifications for chrono types have the following syntax:
    chrono_type: "a" | "A" | "b" | "B" | "c" | "C" | "d" | "D" | "e" | "F" |
               : "g" | "G" | "h" | "H" | "I" | "j" | "m" | "M" | "n" | "p" |
               : "q" | "Q" | "r" | "R" | "S" | "t" | "T" | "u" | "U" | "V" |
-              : "w" | "W" | "x" | "X" | "y" | "Y" | "z" | "Z" | "%" |
+              : "w" | "W" | "x" | "X" | "y" | "Y" | "z" | "Z" | "%"
 
 Literal chars are copied unchanged to the output. Precision is valid only for
 ``std::chrono::duration`` types with a floating-point representation type.
 
 *conversion_spec* are conversion specifiers documented in `strftime
-<http://en.cppreference.com/w/cpp/chrono/c/strftime>`_.
+<http://en.cppreference.com/w/cpp/chrono/c/strftime>`_. Specifiers that have a
+calendaric component such as `'d'` are valid only for ``std::tm`` and not
+durations or time points.
 
 .. _formatexamples: