Currently, when you use the "closest value" aggregation mode, the value that is returned is the last value in the interval, but the time stamp associated with each sample is the START of the interval. This causes very misleading data representation, as each data value will actually be the "closest" value to the following time stamp. In order to show the actual data value closest to each time stamp, custom scripting is required to manually offset the time stamps.

If the "closest value" returns the value at the END of an interval, then the returned time stamp should be the END of that interval. Alternatively, "closest value" should return the value at the START of the interval, to match the returned time stamp. Or even, a new "first value" aggregation mode should be created.

The default functionality should not lead to an inaccurate representation of data, requiring custom scripting just to fix it.