Reset timepicker lable to match time token values

[chiliconbeano]

I have a dashboard containing two radio buttons, one for 'Current quarter' and one for 'Previous quarter'.  I also have a timepicker input field for customizing the time range for a query.  Following is the XML code for the input fields:

    <input type="radio" token="quarter_token" searchWhenChanged="true">
      <label>Select quarter...or...</label>
      <choice value="earliest=@qtr latest=@d">Current quarter</choice>
      <choice value="earliest=-1qtr@qtr latest=@qtr">Previous quarter</choice>
    </input>
    <input type="time" token="time_token" searchWhenChanged="true">
      <label>Select date range</label>
      <change>
        <set token="form.quarter_token"></set>
      </change>
      <default>
        <earliest>@qtr</earliest>
        <latest>@d</latest>
      </default>
    </input>

My question is: How can I reset the timepicker Label text to match the radio button selected time range?  Currently, if a user selects a custom time range, then selects one of the radio buttons, the timepicker label doesn't match the radio button time range selection.  For example, can I simply do the following to reset the timepicker label?

<set token="form.time_token.earliest">@qtr</set>
<set token="form.time_token.latest">@d</set>

In the example attachment, the timepicker lable shows 'Last 55 days' as well as the 'Previous quarter' radio button being selected.  This situation presents an inconsistent UI.

thanks in advance,

Bob