return date object from date/datetime widgets if no format set

CHANGELOG.md

@@ -5,6 +5,12 @@
     Click to see more.
   </summary>
 
+  ## v1
+
+  ---
+
+  ## v2
+  * (possibly breaking): return date object from date/datetime widgets if no format set ([@erquhart](https://github.com/erquhart) in [#1296](https://github.com/netlify/netlify-cms/pull/1296))
 </details>
 
 ## 1.8.2 (May 24, 2018)

src/components/EditorWidgets/Date/DateControl.js

@@ -20,7 +20,7 @@ export default class DateControl extends React.Component {
     includeTime: PropTypes.bool,
   };
 
-  format = this.props.field.get('format') || (this.props.includeTime ? DEFAULT_DATETIME_FORMAT : DEFAULT_DATE_FORMAT);
+  format = this.props.field.get('format');
 
   componentDidMount() {
     const { value } = this.props;
@@ -41,22 +41,34 @@ export default class DateControl extends React.Component {
   handleChange = datetime => {
     const { onChange } = this.props;
 
-    // Set the date only if the format is valid
-    if (this.isValidDate(datetime)) {
+    /**
+     * Set the date only if it is valid.
+     */
+    if (!this.isValidDate(datetime)) {
+      return;
+    }
+
+    /**
+     * Produce a formatted string only if a format is set in the config.
+     * Otherwise produce a date object.
+     */
+    if (this.format) {
       const formattedValue = moment(datetime).format(this.format);
       onChange(formattedValue);
+    } else {
+      const value = moment.isMoment(datetime) ? datetime.toDate() : datetime;
+      onChange(value);
     }
   };
 
   onBlur = datetime => {
-    const { setInactiveStyle, onChange } = this.props;
+    const { setInactiveStyle } = this.props;
 
     if (!this.isValidDate(datetime)) {
       const parsedDate = moment(datetime);
 
       if (parsedDate.isValid()) {
-        const formattedValue = parsedDate.format(this.format);
-        onChange(formattedValue);
+        this.handleChange(datetime);
       } else {
         window.alert('The date you entered is invalid.');
       }
@@ -67,11 +79,10 @@ export default class DateControl extends React.Component {
 
   render() {
     const { includeTime, value, classNameWrapper, setActiveStyle, setInactiveStyle } = this.props;
-    const format = this.format;
     return (
       <DateTime
         timeFormat={!!includeTime}
-        value={moment(value, format)}
+        value={moment(value, this.format)}
         onChange={this.handleChange}
         onFocus={setActiveStyle}
         onBlur={this.onBlur}

website/site/content/docs/widgets/date.md

@@ -12,7 +12,7 @@ The date widget translates a date picker input to a date string. For saving date
 - **Data type:** Moment.js-formatted date string
 - **Options:**
   - `default`: accepts a date string, or an empty string to accept blank input; otherwise defaults to current date
-  - `format`: accepts Moment.js [tokens](https://momentjs.com/docs/#/parsing/string-format/); defaults to ISO8601 format `YYYY-MM-DD`
+  - `format`: optional; accepts Moment.js [tokens](https://momentjs.com/docs/#/parsing/string-format/); defaults to raw Date object (if supported by output format)
 - **Example:**
 
   ```yaml

website/site/content/docs/widgets/datetime.md

@@ -12,7 +12,7 @@ The datetime widget translates a datetime picker to a datetime string. For savin
 - **Data type:** Moment.js-formatted datetime string
 - **Options:**
   - `default`: accepts a datetime string, or an empty string to accept blank input; otherwise defaults to current datetime
-  - `format`: accepts Moment.js [tokens](https://momentjs.com/docs/#/parsing/string-format/); defaults to ISO8601 format `YYYY-MM-DDTHH:mm:ssZ`
+  - `format`: optional; accepts Moment.js [tokens](https://momentjs.com/docs/#/parsing/string-format/); defaults to raw Date object (if supported by output format)
 - **Example:**
 
   ```yaml