The first day of the Iranian calendar falls on the
March equinox, the first day of spring, around March 21.
In the 11th century CE, the Iranian calendar was reformed in order to
fix the beginning of the calendar year, i.e.
Nowruz, at the vernal equinox. Accordingly, the definition of Nowruz given by
the Iranian scientist Tusi was the following: "the first day of the
official New Year [Nowruz] was always the day on which the sun entered
Aries before noon." Nowruz is the first day of Farvardin, the first
month of the Iranian solar calendar.
Iranians also use seven objects in the arrangement of the Nowruz table,
which its names in Persian begin with "S" example: