I'm speaking as the administrator of the election. It's the time required to count the ballots, depending on the system, again I don't want to generalize but subject to the system. You can look at what's currently happening in Australia where there are significant delays in computing, counting, the ballots. One of the main reasons there is that the contests are so close that in their preferential ballot system you have to allocate preferences and that requires several passes at the count.
On July 7th, 2016. See this statement in context.