title: FM to get date within accounting period
body: <p>I'm searching for FM or BAPI that takes any date as a parameter and returns the date within the accounting period.</p>
  <p>I need something which works like this... i.e. Let's say 04/2021 is open as an accounting period.</p>
  <pre><code>Case1: Input Parameter(2/1/2021) -&gt; return(4/1/2021)
  Case2: Input Parameter(4/15/2021) -&gt; return(4/15/2021)
  Case3: Input Parameter(6/1/2021) -&gt; return(4/1/2021)
  </code></pre>