Updated Examples and Recipes (markdown)

Examples-and-Recipes.md

@@ -3,6 +3,7 @@ This page contains examples and recipes contributed by community members. Feel f
 ##Contents
 - [Obtaining a `time_point` from `y/m/d h:m:s` components](#time_point_to_components)
 - [Obtaining `y/m/d h:m:s` components from a `time_point`](#components_to_time_point)
+- [Normalizing `y/m/d` when it is `!ok()`](#normalize)
 
 ***
 
@@ -99,6 +100,33 @@ std::cout << t.tm_year << "-" << t.tm_mon << "-" << t.tm_day << " ";
           << t.tm_hour << ":" << t.tm_min << ":" << t.tm_sec << "\n";
 
 ```
+<a name="normalize"></a>
+### Normalizing `y/m/d` when it is `!ok()`
+(by [Howard Hinnant](https://github.com/HowardHinnant))
+
+The following function will "normalize" a `year_month_day`, much like `mktime` normalizes a `tm`.  This function is not part of the library, but is offered as an example if you find your self needing things like this:
+
+    date::year_month_day
+    normalize(date::year_month_day ymd)
+    {
+        using namespace date;
+        ymd += months{0};
+        ymd = day_point(ymd);
+        return ymd;
+    }
+
+The first line simply adds 0 months to the `ymd`.  If `ymd.month()` is 0, with will subtract one from the `year` and set the month to `Dec`.  If `ymd.month()` is greater than 12, the year will be incremented as many times as appropriate, and the month will be brought within the proper range.  This operation will do nothing if `ymd.month().ok()` is already true.
+
+The second line will "normalize" the day field.  The second line requires that the month field is already normalized.  For example `2015_y/dec/32` will become `2016_y/jan/1`.  If the day field is already in range, there will be no change.
+
+The conversion from `year_month_day` to `day_point` calls this algorithm:
+
+http://howardhinnant.github.io/date_algorithms.html#days_from_civil
+
+And the conversion from `day_point` back to `year_month_day` calls this algorithm:
+
+http://howardhinnant.github.io/date_algorithms.html#civil_from_days
+ 
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