Rasulullah (Allah bless him & give him peace) said: “The word “shaahid” refers to Friday . There is no day more virtuous than Friday. There is such an hour in this day that no Muslim will make dua in it except that his dua will be accepted. And he does not seek protection from anything except that Allah Ta’ala will grant him protection . “
(Tirmidhi)
The word “shaahid” appears in Surah Burooj . Allah Ta’ala has taken an oath of that day.
ALLAH says in the Quran:
“By the sky in which there are constellations .By the promised day (of judgement). By the day that witnesses (Friday), and the day that is witnessed (day of Arafah). “
google knows it 😀