The last day of Zilhajj is the last day in the Arabic calendar. According to some narrations mentioned by Sayyid Ibn Tawus in his book of Iqbal al-A’mal, it is recommended to offer a two unit prayer on this day reciting Surah al-Faatehah once, and repeating each of Surah al-Tawheed and Ayah al-Kursi ten times. After accomplishment, it is recommended to say the following supplicatory prayer:
اللّٰهُمَّ مَا عَمِلْتُ فِي هَذِهِ السَّنَةِ مِنْ عَمَلٍ نَهَيْتَنِي عَنْهُ وَ لَمْ تَرْضَهُ وَ نَسِيتُهُ وَ لَمْ تَنْسَهُ وَ دَعَوْتَنِي اِلَى التَّوْبَةِ بَعْدَ اجْتِرَائِي عَلَيْكَ اللّٰهُمَّ فَاِنِّي اَسْتَغْفِرُكَ مِنْهُ فَاغْفِرْ لِي وَ مَا عَمِلْتُ مِنْ عَمَلٍ يُقَرِّبُنِي اِلَيْكَ فَاقْبَلْهُ مِنِّي وَ لا تَقْطَعْ رَجَائِي مِنْكَ يَا كَرِيمُ
If these statements are said, Satan will say, “Woe to me! All the efforts that I have exerted throughout this year for misleading this person have been failed by the utterance of these statements.” Besides, one who says these words will be testified by the year that he sealed it in a good way.