Dua for keeping a fast (Sehri)
It is highly advised not to neglect the suhur (meal before starting fast) even if a single date or drink of water are had. A Hadith reads that Almighty Allah and his angels bless those who seek forgiveness in the last hours of the night and have the meal before starting their fasts.
It is recommended to recite Sura Qadr at the time of sahar for a Hadith reads that any believer who recites Sura Qadr at the meal before starting the fast and the meal of breaking the fast (iftar) will be rewarded as sacrificing his blood for the sake of Almighty Allah between these two periods.
Surah Qadr(Chapter 97)
Innaa Anzalnaahu Fiy Laylatil Qadr Wa Maa Adraaka Maa Laylatul Qadr Laylatul Qadri Khayrum Min Alfi Shahr Tanazzalul Malaaikatu War Ruuhu fiyhaa Bi Idhni Rabbihim Min Kulli Amr Salaamun Hiya Hattaa Matla’Il Fajr
Surely We revealed it on the grand night.And what will make you comprehend what the grand night. The grand night is better than a thousand months. The angels and Jibreel descend in it by the permission of their Lord for every affair, Peace! it is till the break of the morning.
Dua for breaking a fast (Iftar )
اللَّهُمَّ اِنِّى لَكَ صُمْتُ وَبِكَ امنْتُ [وَعَلَيْكَ تَوَكَّلْتُ] وَعَلَى رِزْقِكَ اَفْطَرْتُ[“wa ‘alayka tawakkaltu” is quoted in some books of knowledge – but not all, hence it is in brackets] [Abu Dawud]
It is advisable to say the following at the first bite of food with which the fasting is broken:
Bismillahir Rah’maanir Rah’eem Yaa Eaasi—a’l Eaghfirati Igfir Lee