SQL:How to group the dates from a certain date of each month
<p>I need to group the sales date starting from a certain date. The date is determined by the date when the sales data is exported. In the example below is the data is exported on 2016/11/10. </p>

<p>Then the sales date should be grouped into the yellow column to calculate the sales during each period.</p>

<p>I tried the dateadd function, but since the each month might have different different days, so it doesn't work.</p>

<p>Any suggestion would be greatly appreciated. Thanks.</p>

<p><a href="https://i.stack.imgur.com/V3aPk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/V3aPk.png" alt="enter image description here"></a></p>