headingLevel

Controls the heading level of the calendar’s toolbar title, affecting its position in the document’s heading hierarchy.

The toolbar title is rendered as a <div> with an aria-level attribute, functioning like an <h1>, <h2>, etc. in the document outline without affecting visual appearance. Set this to match the surrounding page structure so screen readers can navigate the calendar title at the appropriate level.

new Calendar(calendarEl, {
  headingLevel: 3 // equivalent to <h3> in the document outline
})