title: Is it possible to store date as meta_key in wordpress?
body: <p>I'm trying to store dates and holidays in post_meta in wordpress database. I made a custom post type to store this data. So in table wp_post, I store _event_date = date and _event_holiday = holiday. The problem is that I can't query which date has the holiday I want to query. So I was thinking to store the dates in "meta_key" fields, but they say the values that are stored in meta_keys needs to have underscore. So I am hesitate to do it.   <br> <br></p>
  
  <p>My current codes is as follows. <br></p>
  
  <p>This is how I store my current data in wp_postmeta.</p>
  
  <pre><code>add_post_meta($post-&gt;ID, "_event_name", $_POST["_event_name"]);
  add_post_meta($post-&gt;ID, "_event_date", $_POST["_event_date"]);
  </code></pre>
  
  <p>This is what I want to do instead. <br></p>
  
  <pre><code>add_post_meta($post-&gt;ID, $_POST[_event_date], $_POST["_event_name"]);
  </code></pre>
  
  <p>Would this method have problems with wordpress or something?</p>