title: How to add days to a DateTime variable with custom format
body: <p>I'm using two DateTime Pickers each with a custom format &quot;dd-MMM-yy&quot;
  I try to add one day to them but it isn't working.</p>
  <p>Here's my code:</p>
  <pre><code>DateTime current = from_txt.value;
  current.AddDays(1);
  </code></pre>
  <p>DateTime Picker from_txt properties.</p>
  <pre><code>custom format = &quot;dd-MMM-yy&quot;
  Format = custom format
  </code></pre>
  <p>I want to add one day as I said before without changing the format. Is it possible?
  Thanks in advance</p>