This site uses this specific heading for its guarantee section: "Two Months To Decide" — worth understanding precisely what that framing describes.
This site directly connects the 60-90 day evaluation window to the full 60-day guarantee, describing the guarantee as giving genuine room to try SodaPeak risk-free before deciding.
Since most customers are described as staying consistent for 60-90 days, the guarantee gives real room to judge results within that stated window, rather than deciding on day one or two.