Power BI charts with monthly data default to long month names ("January") or three-letter abbreviations ("Jan") — both consume axis space. Single letters are more compact, but J appears in January, June, and July. Power BI treats them as the same value, collapses duplicates in slicers, and sorts them alphabetically. The zero-width space (ZWS) trick makes each letter visually identical but internally unique by appending N invisible characters to the Nth month. This skill creates the column, sets the sort-by relationship to the numeric month column, and optionally rewires the chart axis in one command.