>
        The function returns 0 on success and a negative value in case of
        error.
       </p></dd><dt id="ECPG-INFORMIX-FUNCTIONS-DTSUB"><span class="term"><code class="function">dtsub</code></span> <a href="#ECPG-INFORMIX-FUNCTIONS-DTSUB" class="id_link">#</a></dt><dd><p>
        Subtract one timestamp from another and return a variable of type
        interval.
</p><pre class="synopsis">
int dtsub(timestamp *ts1, timestamp *ts2, interval *iv);
</pre><p>
        The function will subtract the time