Well, the Hijri date 16 Shawwal 1404 corresponds to the Gregorian date Sunday, 15 July 1984. This date lies in the tenth month of the Hijri year 1404 AH, which is Shawwal of 1404 AH. Both this Hijri and Gregorian date occur on the single day that is Sunday without any doubt. The Arabic date 1404/10/16 is calculated using the Umm Al-Qura calendar and the sighting of the moon. One thing to remember is that this Arabic date may occur on different Gregorian date depending upon the region and country and obviously the moon.
If you are still not sure about the date then you can use our Arabic date converter.
The following is the conversion of the Gregorian date 15 July 1984 to its equivalent Arabic date.
The following is the conversion of the Arabic date 16 Shawwal 1404 AH to its equivalent Gregorian date.
قُلْ يَٰقَوْمِ ٱعْمَلُوا۟ عَلَىٰ مَكَانَتِكُمْ إِنِّى عَٰمِلٌۭ ۖ فَسَوْفَ تَعْلَمُونَ
Say: O my people! Act in your manner. Lo! I (too) am acting. Thus ye will come to know
Surah Az-Zumar(39:39)
Sahih al-Bukhari
Fasting
Chapter: Observing Saum on the first day of 'Eid-ul-Adha.
Narrated Abu Sa`id Al-Khudri:
(who fought in twelve Ghazawat in the company of the Prophet). I heard four things from the Prophet (ﷺ) and they won my admiration. He said; -1. "No lady should travel on a journey of two days except with her husband or a Dhi-Mahram; -2. "No fasting is permissible on the two days of Id-ul-Fitr and `Id-ul-Adha; -3. "No prayer (may be offered) after the morning compulsory prayer until the sun rises; and no prayer after the `Asr prayer till the sun sets; -4. "One should travel only for visiting three Masjid (Mosques): Masjid-al-Haram (Mecca), Masjid-al- Aqsa (Jerusalem), and this (my) Mosque (at Medina).
Sahih al-Bukhari 1995