title: how to add geom_text labels at the bottom of each group in ggplot2
body: <p>I am trying to add dates below each grouped bar i.e. between 0 of y-axis and product labels at x-axis. Listed is a reprex.</p>
  
  <pre class="lang-r prettyprint-override"><code>df1 &lt;- data.frame(product = c("A","A","A","A","A","A","A","B","B","B","B","B","B","B","C","C","C","C","C","C","C","D","D","D","D","D","D","D"), 
                    start_date =as.Date(c('2020-02-01', '2020-02-02', '2020-02-03', '2020-02-04', '2020-02-05', '2020-02-06', '2020-02-07')),
                    value = c(15.71,17.37,19.93,14.28,15.85,10.5,8.58,5.62,5.19,5.44,4.6,7.04,6.29,3.3,20.35,27.92,23.07,12.83,22.28,21.32,31.46,34.82,23.68,29.11,14.48,25.2,16.91,27.79))
  
  graph &lt;- ggplot(df1, aes(y = value, x = product, fill = product, group = factor(start_date))) +
    geom_col(data = df1, stat = "identity",position = position_dodge(width = 0.8), width = 0.7, inherit.aes = TRUE, size = 0) + 
    geom_text(aes(label= format(as.Date(start_date,format="%Y-%m-%d"), format = "%d")), vjust = "bottom", position = position_dodge(width = 0.8), inherit.aes = TRUE) +
    xlab("Product") + ylab("Values") 
  </code></pre>
  
  <p>Even if I adjust vjust or hjust values I get the below plot
  <a href="https://i.stack.imgur.com/R4Crv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/R4Crv.png" alt="enter image description here"></a></p>
  
  <p>I would like the dates similar to the plot below
  <a href="https://i.stack.imgur.com/DSelj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DSelj.png" alt="enter image description here"></a></p>