How to convert this date in dropdown in dashboard

[supreme_coder]

how do I covert the date that is in dropdown to "Y-M-D". 

I dont want the other stuff next to it (T00:). 

index="main" | eval _time = strptime('close_approach_data{}.close_approach_date', "%Y-%m-%d") | table _time | dedup _time

[ITWhisperer]

      <input type="dropdown" token="datefilter">
        <label>Select Date</label>
        <search>
          <query>index="main" | eval date = strptime('close_approach_data{}.close_approach_date', "%Y-%m-%d") | table date | dedup date | eval showdate=strftime(date, "%Y-%m-%d")</query>
        </search>
        <fieldForLabel>showdate</fieldForLabel>
        <fieldForValue>date</fieldForValue>
      </input>