Said Ibn Qayyim Al-Jauziyyah - may Allâh bestow mercy on him.

فَاَللّهُ سُبْحَانَهُ جَعَلَ لِأَهْلِ كُلّ مِلّةٍ يَوْمًا يَتَفَرّغُونَ فِيهِ لِلْعِبَادَةِ وَيَتَخَلّوْنَ فِيهِ عَنْ أَشْغَالِ الدّنْيَا فَيَوْمُ الْجُمُعَةِ يَوْمُ عِبَادَةٍ وَهُوَ فِي الْأَيّامِ كَشَهْرِ رَمَضَانَ فِي الشّهُورِ وَسَاعَةُ الْإِجَابَةِ فِيهِ كَلَيْلَةِ الْقَدْرِ فِي رَمَضَانَ . وَلِهَذَا مَنْ صَحّ لَهُ يَوْمُ جُمُعَتِهِ وَسَلِمَ سَلِمَتْ لَهُ سَائِرُ جُمْعَتِهِ وَمَنْ صَحّ لَهُ رَمَضَانُ وَسَلِمَ سَلِمَتْ لَهُ سَائِرُ سَنَتِهِ وَمَنْ صَحّتْ لَهُ حَجّتُهُ وَسَلِمَتْ لَهُ صَحّ لَهُ سَائِرُ عُمْرِهِ فَيَوْمُ الْجُمُعَةِ مِيزَانُ الْأُسْبُوعِ وَرَمَضَانُ مِيزَانُ الْعَامِ وَالْحَجّ مِيزَانُ الْعُمْرِ . وَبِاَللّهِ التّوْفِيقُ

Allâh the Mighty has made for people of every religion a day in which they worship Allâh and shun every mundane distractions. The day of Jumu’ah is indeed a day of worship, it is like as Ramadan is to the months, the hour therein where supplications are granted are like Laylatul-Qadr in Ramadan. Therefore whoever attains a successful day of Jumu’ah, the rest of his week days will be normal for him. So also whoever has a successful Ramadan, the rest of the days of that year will be normal for him. Whoever also has a successful Hajj, the rest of his life time will be successful. The day of Jumu’ah is the standard of a week, Ramadan is the standard of a year and Hajj is the standard of a lifetime.’

Zâdul-Ma‘âd, 1/384.