>Description</th></tr></thead><tbody><tr><td><code class="literal">AM</code></td><td>Time is before 12:00</td></tr><tr><td><code class="literal">AT</code></td><td>Ignored</td></tr><tr><td><code class="literal">JULIAN</code>, <code class="literal">JD</code>, <code class="literal">J</code></td><td>Next field is Julian Date</td></tr><tr><td><code class="literal">ON</code></td><td>Ignored</td></tr><tr><td><code class="literal">PM</code></td><td>Time is on or after 12:00</td></tr><tr><td><code class="literal">T<