The Kaaba’s cover (Kiswah) is traditionally changed once a year.
Time of Replacement:
The veil was usually changed on the beginning of the Hijri year, on the first day of the month of Muharram.
However, in recent years, Saudi Arabia has changed this tradition to coincide with the ninth day of the month of Dhu al-Hijjah, the Day of Arafat.
Significance of this Change: Changing the veil on the Day of ‘Arafat ensures that all pilgrims and the Islamic world will have the opportunity to see the Ka’bah the next day (the first day of Eid al-Adha) with its new and clean veil. This is a spiritual tradition that millions of Muslims follow live every year.