Transform an Excel matrix into values separated by commas

I have a Matrix where column A has people name, then each column is has a date on the first line. For each line (person) ti can have the value 1 on the cell.

I would like to "reduce" this matrix to a single value per line (array), separated by commas.

Basically that's what I have:

Column A | Column B | Column C | Column D | ... | 
Person   | 01/Jan   | 02/Jan   | 03/Jan   | ... |
John     | 1        |          |          | ... |
Paul     |          |          | 1        | ... |
Megan    | 1        |          | 1        | ... |

What I would like to have is (in another tab) a table like this:

Column A | Column B       | 
John     | 01/Jan         |
Paul     | 03/Jan         |
Megan    | 01/Jan, 03/Jan |