Datetime-local input doesn't accept the specified value
<p>I have a datetime-local input.</p>

<p>I wish I had the ability to mandatory specify a date and optionally an hour.</p>

<p>Only, even when I indicate both, a warning occurs preventing me to get the input value.</p>

<p>Here is the warning message in question:</p>

<pre><code>The specified value "0000-00-00T00:00" does not conform to the required format. The format is "yyyy-MM-ddThh:mm" followed by optional ":ss" or ":ss.SSS".
</code></pre>

<p>I don't see where does the error or how to solve it.</p>