Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:74:9 –

That Day will be a difficult day  

that day, that is to say, the time of the sounding (yawma’idhin is a substitution for the preceding subject, and is not declined because it is annexed to something that cannot be declined; the predicate of the subject ˹is the following˺) will be a harsh day (idhā is operated by what is indicated by the statement: ishtadda’lamru, ‘˹for when the trumpet is sounded˺ the situation will be terrible’),
القرآن:٧٤:٩ –

فَذَٰلِكَ يَوْمَئِذٍ يَوْمٌ عَسِيرٌ  

{فذلك} أي وقت النقر {يومئذ} بدل مما قبله المبتدأ وبني لإضافته إلى غير متمكن وخبر المبتدأ {يوم عسير} والعامل في إذا ما دلت عليه الجملة اشتد الأمر.