Fix #576 added logic to ensure AM and PM values are all calculated correctly.

Author: c-eiser13

src/controls/dateTimePicker/DateTimePicker.tsx

@@ -125,9 +125,17 @@ export class DateTimePicker extends React.Component<IDateTimePickerProps, IDateT
       }
 
       if (this.props.timeConvention !== TimeConvention.Hours24) {
-        if (hoursSplit[1] && hoursSplit[1].toLowerCase().indexOf("am") !== -1) {
+        if (hoursSplit[1] && hoursSplit[1].toLowerCase().indexOf("pm") !== -1) {
           hours += 12;
           if (hours === 24) {
+            //this is noon - set to 12 not 0
+            //hours = 0;
+            hours = 12;
+          }
+        }
+        else {
+          //am - if hours == 12, set hours to 0 here
+          if (hours == 12){
             hours = 0;
           }
         }