Calculated fields are handy when one needs to group reports by month/quarter. It creates a cleaner chart and allows for more aggregated data points. However, a surprising limitation is that if you drag this calculated DATE field into a chart for trend lines, it doesn't sort by date, but alphabetically by text. As you can see, the Jan 2022 value is coming before the Sept 2021 values. There doesn't seem to be any other way of grouping dates and plotting trend lines.
This idea is to request a sorting mechanism so that we can have trendlines with properly sorted dates.
Thank you – we will consider this improvement for the future. Until then, formatting the date numerically (%Y - %m) will present the dates in order.