+ An array of line objects to display on the chart. +
++ Controls how timestamps are formatted on the X-axis legend and tooltip. + Does not affect data aggregation — only the display format. +
+'days' — shows day and month (e.g., "19 dec")'hours' — shows day, month, and time (e.g., "19 dec, 14:00")'minutes' — shows day, month, and time (e.g., "19 dec, 14:30")