      because of a failed checksum). If the hardware simply doesn't support it, then the driver should not emit a
            value at all.</p>

        <p>However, the time value must never be <span class="code">None</span>. This is because it is used as the
            primary key in the SQL database. </p>

        <h1>Time</h1>

        <p>WeeWX stores all data in UTC (roughly, &quot;Greenwich&quot; or &quot;Zulu&quot;)
            time. However, usually one is interested in weather events in local time 