Hi Firtina,
I think you've a bit strange approach with using the dates as fieldcatalogue names (something which should be static), also wondering what should happen when you find an additional clock entry, should it then display 4 entries? Or what should happen when you select two persons with different clock dates, say pers 1 has 18.01, 19.01 and 20.01, since person 2 has 19.01, 20.1 and 22.1?
If that should be the case, I would recommend to use Run Time Types and usages of timestamps as fields (so the date and the time can be concatenated). But this will be quite a long answer to fully explain what I should tell you here.
But for a quick fix on your direct requirements and direct needs, you should delete two rows from the internal table you are displaying in the ALV (class, function module) and concatenate the data of one person.
Best,
Sander