What will next month bring, if nothing changes?

One synthetic advertiser’s daily conversions. You set how much history the forecast gets, how fast the account is really growing and how noisy its days are. The method fits the trend, the weekly rhythm and the leftover, and draws next month with its range. Tell it about a change you already know is coming and watch the forecast fail to see it. Synthetic data throughout.

Days of history: 180

Real growth per quarter: +25%

Day-to-day wobble: 12%

A change you already know about, from day 10: none

history forecast 90% range, day by day

Show the numbers as a table

Day ahead	Forecast	Low	High

Self-check: running…