How can I calculate a fiscal week
<p>I would like a column displaying the fiscal week.  Our fiscal year begins in April.</p>

<p>So far I have the below, using     datename(ww,DateAndTime) as Week</p>

<pre><code>DateAndTime                 Week 
2015-04-01 22:45             14
2015-06-14 13:22             25
2015-12-02 09:15             49
2016-01-01 07:35              1
</code></pre>

<p>I would like the output to show:</p>

<pre><code>DateAndTime                 Week            Fiscal Week 
2015-04-01 22:45             14                  1
2015-06-14 13:22             25                 12 
2015-12-02 09:15             49                 36              
2016-01-01 07:35              1                 41
</code></pre>