title: Unable to get the initial date of the month using withDayOfMonth
body: <p>I want to get the first datetime of the month for the given date-time as follows: For the date <code>19-04-2018 19:00:00</code> (dd-MM-yyyy HH:mm:ss) it should be <code>01-04-2018 00:00:00</code>.</p>
  
  <p>I have tried the below code, but it gives the empty list.</p>
  
  <p><code>startDate</code> may contains the value like <code>01-04-2018 00:00:00</code>.</p>
  
  <pre><code>List&lt;scPosR&gt; scPosRListPerStoreAndTimeStamp =  spst.stream().filter(
                  scPosR -&gt; Timestamp.valueOf(scPosR.getTransactionDate()
                          .toLocalDateTime()
                          .toLocalDate()
                          .withDayOfMonth(1)
                          .atStartOfDay())
                  .equals(startDate))
          .collect(Collectors.toList());
  </code></pre>
  
  <p>Can anyone please suggest me to do it?</p>