What's the Opposite of "most_recent"

I'm updating my categories and how some of my series display on my channel. All of my series are currently displayed in reverse chronological order with the most recent episode appearing first. In the categories section of my JSON files, the order is set up like this:

   {
      "name": "Strange Tapes Strange Show",
      "query": "Strange Tapes",
      "order": "most_recent"
    },

Instead of "most_recent" what would I write under the "order" option to display the oldest video first?  Thanks for any advice.