Problem
Sprint end dates are mapped to the end of a day within Portfolio. That is, if there is a sprint ending on 15/Jun/16, 11:23:17, Portfolio will map its end date to 15/Jun/16, 23:59:59. Similar, sprint start dates are mapped to the beginning of the respective day. This is due to Portfolio scheduling on a day-granularity and hence timestamps have to be mapped to either the start or end of a day. As a consequence, the duration of that sprint might appear longer by one day than it actually is. For instance, a sprint running from 15/Jun/16, 11:23:17 - 16/Jun/16, 11:23:16 would have a duration of 2 days in Portfolio even though its actual duration is just one day. This leads to an inflated capacity for that sprint.

Expected behaviour
The sprint duration should be accurate, however, due to Portfolio's day granularity, the sprint start/end timestamps cannot be matched, a better heuristic might help (mapping timestamps from the afternoon to end-of-day, mapping timestamps from before noon to beginning-of-day).