When is Ashura 2031?

Ashura is fixed in the Hijri calendar, which is purely lunar with no leap month at all. Twelve lunar months run about eleven days shorter than a solar year, so the Gregorian date walks steadily backwards through the seasons and returns to the same point roughly every thirty-three years — 11 days earlier than in 2030.

Which dates fall near Ashura changes every year, because the calendars move against each other.