The EXPAND Procedure

If no frequency conversion is done, the range of output observations is the same as in the input data set.

When frequency conversion is done, the observations in the output data set range from the earliest start of any result series to the latest end of any result series. Observations at the beginning or end of the input range for which all result values are missing are not written to the OUT= data set.

When the EXTRAPOLATE option is not used, the range of the nonmissing output results for each series is as follows. The first result value is for the TO= interval that contains the ID value of the start of the FROM= interval containing the ID value of the first nonmissing input observation for the series. The last result value is for the TO= interval that contains the end of the FROM= interval containing the ID value of the last nonmissing input observation for the series.

When the EXTRAPOLATE option is used, result values for all series are computed for the full time range covered by the input data set.