THE GREAT MOSQUE OF DEMAK it is said that it is a representation of the Great Mosque of Demak that was founded by Raden Fatah with Wali Songo by giving a similar image of bulus which is candra sengkala memet, with the meaning of “Sirna Ilang Kertaning Bumi” which means the year 1401 Saka. Bulus image consists of the head which means the number 1 (one), 4 feet means the number 4 (four), body bulus means the number 0 (zero), tail bulus means the number 1 (one). From this symbol, it is estimated that the Great Mosque of Demak was founded in 1401 Saka and this mosque was founded on 1 Shafar.
The mosque has the main buildings and Portico associated with the eight saka majapahit. The main building has four main pillars called saka guru. One of the main pillars is said to come from wood chips made by Kanjeng Sunan Kalijaga, so named saka tatal.
The porch building is an open building and its roof is in The Shape of a pyramid supported by eight pillars called Saka Majapahit. The roof of the pyramid of the mosque consists of three parts depicting faith, Islam, and Ihsan. In this mosque there is also a” Bledeg door "lightning door, drawn Ki Ageng Selo containing candra sengkala, which can be read “Naga Mulat Salira Wani" with the meaning of the year 1388 Saka or 1466 M, or 887 H.
