title: Can I create a timeline in timevis based on age instead of dates?
body: <p>I'm using timevis for my project. I need to make a timeline of activities in a person's life. However, the data I was given only contains the years each activity started and ended (for example, renting an apartment start in 2016 and end in 2021) and the person's age at the start and end of the activity (for example, renting apartment start is age 40.56 and end is 45.23).</p>
  <p>Ideally, I need to be able to make the timeline based on the age range, not the year range. Is there a way to change timevis from making a timeline based on dates and instead make the timeline based on age?</p>
  <p>Right now I have:</p>
  <pre class="lang-r prettyprint-override"><code>timevis(data = data.frame(
    start = c(&quot;2014&quot;, &quot;2016&quot;, &quot;2020&quot;),
    end = c(&quot;2015&quot;, &quot;2018&quot;, &quot;2021&quot;),
    content = c(&quot;Item One&quot;, &quot;Item Two&quot;, &quot;Item Three&quot;),
    group = c(1, 2, 3)),
    groups = data.frame(id = 1:3, content = (&quot;G1&quot;, &quot;G2&quot;, &quot;G3&quot;))
  ) %&gt;%
    setGroups(data.frame(id = 1:3, content = c(&quot;Group 1&quot;, &quot;Group 2&quot;, &quot;Group 3&quot;)))
  
  timevis(data)
  </code></pre>
  <p>I tried putting ages instead of dates and it doesn't work.</p>
  <p>Thank you!</p>