What is the religious significance of soyem (third day after death) and Arbaeen (40 days after death). We usually arrange a family gathering in these days and pray for the forgiveness of the deceased.
Arranging a gathering for reciting the Holy Quran and praying for the forgiveness of the deceased is a recommended practice in Islam that can take place any day of the year. As for designating a day like the 3rd, 7th, or 40th, or after one year, these are cultural norms, and since they do not conflict with the teachings of Islam, it is permissible to hold and attend such gatherings.