A portrait

I went to work even on Saturday, because I wanted  to give  possibility to participate to my study  for those who are working on weekdays. So I woke up before seven to be in time.  And what happened!  Only the last of the four subjects   arrived.
And none of those who missed did not inform anything for me beforehand.  So I had been able to sleep longer.

 Fortunately this family had got a wrong address and I gave them possibility to a portrait.  So it was not for nothing to arrive to work on Saturday!