Improve documentation on default values when building date for onChange callback

Author: wojtekmaj

README.md

@@ -112,7 +112,7 @@ Displays an input field complete with custom inputs, native input, a calendar, a
 | nativeInputAriaLabel | `aria-label` for the native datetime input.                                                                                                                                                                                                                                                                                        | n/a                     | `"Date"`                                                                                                       |
 | onCalendarClose      | Function called when the calendar closes.                                                                                                                                                                                                                                                                                          | n/a                     | `() => alert('Calendar closed')`                                                                               |
 | onCalendarOpen       | Function called when the calendar opens.                                                                                                                                                                                                                                                                                           | n/a                     | `() => alert('Calendar opened')`                                                                               |
-| onChange             | Function called when the user clicks an item on the most detailed view available.                                                                                                                                                                                                                                                  | n/a                     | `(value) => alert('New date is: ', value)`                                                                     |
+| onChange             | Function called when the user picks a valid datetime. If any of the fields were excluded using custom `format`, `new Date(y, 0, 1, 0, 0, 0)`, where `y` is the current year, is going to serve as a "base".                                                                                                                        | n/a                     | `(value) => alert('New date is: ', value)`                                                                     |
 | onClockClose         | Function called when the clock closes.                                                                                                                                                                                                                                                                                             | n/a                     | `() => alert('Clock closed')`                                                                                  |
 | onClockOpen          | Function called when the clock opens.                                                                                                                                                                                                                                                                                              | n/a                     | `() => alert('Clock opened')`                                                                                  |
 | openWidgetsOnFocus   | Whether to open the widgets on input focus.                                                                                                                                                                                                                                                                                        | `true`                  | `false`                                                                                                        |