FORECAST.ETS Function

[BobH]

I need help understanding the arguments in this function. I've attached a spreadsheet that I'd like to use it on. What I expect the formula to do is to forecast values for dates not yet reached. The data is daily and meets the requirements of the formula (I think). I think I have defined the first 2 arguments correctly, but I am uncertain what the timeline argument should contain. It is also possible that I am trying to use the function incorrectly. The data are kilowatt hours of daily electricity consumption.

The function's syntax is: =FORECAST.ETS(target_date, values, timeline, [seasonality],[data_completion],[aggregation]).

All suggestions will be greatly appreciated and shall be gratefully received.

[HansV]

The formula in row 18 would be

=FORECAST.ETS(B18,$F$2:$F$17,$B$2:$B$17)

B18 is the first date without data.
$F$2:$F$17 is the list of known kWh use.
$B$2:$B$17 is the list of dates of known use.

Fill down to row 33.

But there is little point in using FORECAST.ETS here, since there is no discernible pattern to the usage data. It would be different if there was a weekly pattern, for example a dip or peak during the weekends. You might as well use the TREND function which provides a linear extrapolation.

See the attached workbook.

forecastets.xlsx

[BobH]

Thank you, Mr. V!