Unfortunately the extrapolation (forecast) is not provided by the site directly but you get coefficients from which you can easily compute forecasted value yourself. Copypasting from Google sheets into the cell grid is also cool feature. – Tomáš Záluský Oct 28 '18 at 15:50
User Manual For Gantt Charts in Google Sheets Lexie Wilson Utah Division of Air Quality. [email protected] (801) 536 – 0022. Contact if you have any questions.