title: Excel sumifs until a new value in column
body: <p>I have some data that looks like:</p>
  
  <pre><code>Day       Result 
  1-Nov       1 
              0
              1
  2-Nov       1
  3-Nov       0
              0
  4-Nov       1     
  </code></pre>
  
  <p>There are other columns with data. I only have the date once as the data is displayed graphically in a time series.</p>
  
  <p>Now I'd like to setup a summary table that aggregates each day. I cannot use <code>sumifs</code>  because the date is only in the data once. </p>
  
  <p>How could I write a calculation such that excel sees a2 has a value so sums b2,b3,...bi until ai has a value.</p>
  
  <p>Preferably not vba, never learned it and want to do this in excel rather than R or Python. </p>
  
  <p>EDIT:</p>
  
  <p>I am specifically looking at how to do calculations on the result column grouped by each date. Blank cells should be considered the same date. So when excel sees 1-Nov it then does a calculation (i've said sum but any we can extend to) on 1,0,1 and then stops and a new calculation is done for Nov-2.</p>