Jummah is considered the best day of the week. Why is it so important?
The purpose of this question is to have detailed, high quality answers detailing the importance of Jummah.
Among the seven days of the week, Friday is the day when Allah's Special mercies are granted. It is a day of gathering for the Muslims and rewards are increased. Many great events took place on this day, and yet to take place.
I'll try enlightening the significance of The Jummah:
Allah has blessed us a complete surah about Jummah
"O you who have believed, when [the adhan] is called for the prayer on the day of Jumu'ah [Friday], then proceed to the remembrance of Allah and leave trade. That is better for you, if you only knew." [Al-Quran 62:9]
The day of Jumu'ah includes an hour during which all supplications are accepted. Abu Hurayrah, narrated that the Messenger of Allaah (ﷺ) said:
"On (the day of) Jumu'ah is an hour during which Allaah gives to a Muslim servant standing in prayer whatever he asks for.”[Al-Bukhaari and Muslim].
The Messenger of Allaah (ﷺ), said:
“The best day the sun rises over is Friday; on it Allaah created Aadam. On it, he was made to enter paradise, on it he was expelled from it, and the Last Hour will take place on no other day than Friday.”[Ahmad and At-At-Tirmithi].
The charity given in this day is more virtuous than the other days of a week. The Messenger (ﷺ) said:
"Charity given during the day of Jumu'ah is greater (in reward) than any other day."
It is a day on which sins are forgiven, as narrated by Salmaan (Ra.) who narrated that the Prophet, (ﷺ) said:
“Any man who performs Ghusl on Friday, perfumes himself if he has perfume, wears the best of his clothes, then goes to the mosque and offers as many prayers as he wishes while not harming anybody, then listens quietly while the Imaam speaks until he offers the prayer, will have all his sins between that Friday and the next forgiven.” [Al-Bukhaari].
Dying on Friday, during the day or night, is a sign of a good end, for the one who dies on that day will be protected from the trial of the grave (i.e., Allaah The Almighty will enable such a person to be steadfast during it). The Prophet, (ﷺ) said:
“Any Muslim who dies during the day or night of Friday will be protected by Allaah from the trial of the grave.” [At-Tirmithi and Ahmad].
It was narrated from Aws ibn Aws al-Thaqafi that the Messenger of Allah (ﷺ) said:
Whoever does Ghusl on Friday and causes (his wife) to do Ghusl, and sets out early, and comes close to the imam and listens and keeps quiet, for every step he takes he will have the reward of fasting and praying qiyaam for one year.” (al-Tirmidhi, 496)