| GetAccumulatedValue(DateTime, DateTime) | Get boundary value accumulated over the specified period. It is the callers responsibility to check if the item is applicable at the given datetime before calling GetAccumulatedValue. If the item is only applicable over a part of the interval, it must return the accumulated value for that part of the interval. |
| GetAccumulatedValue(DateTime, DateTime, TimeSpan) | Method supporting items implementing GetAccumulatedValue(DateTime, DateTime, TimeSpan) |