Bridget O'Donnell, the partner of JW wrote this, proceeds of her article (she's a journalist) donated to the Find Madeleine Fund, worthy to read the whole article
''Our baby would not sleep and at about 8.30pm, Jes took him out for a walk in the buggy to settle him. Gerry was on his way back from checking on his children and the two men stopped to have a chat. They talked about daughters, fathers, families. Gerry was relaxed and friendly. They discussed the babysitting dilemmas at the resort and Gerry said that he and Kate would have stayed in too, if they had not been on holiday in a group. Jes returned to our apartment just before 9.30pm. We ate, drank wine, watched a DVD and then went to bed. On the ground floor, a completely catastrophic event was taking place. On the fourth floor of the next block, we were completely oblivious.''
http://www.guardian.co.uk/uk/2007/dec/14/ukcrime.madeleinemccannIt would seem reading this article and statements, he had walked around basically in circles for approximately an hour, probably why he actually lost track of time. However, pushing a baby around for an hour or so, is a rather long time. But he was the eyes and ears of what was going on in the area.