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.
darimi:871Muḥammad b. Yūsuf > Sufyān Balaghanī > Anas

[Machine] He said, "The minimum duration of menstruation is three days." Abd Allah Al-Dārimī was asked if he agrees with this, to which he replied, "Yes, if that's her usual habit." I also asked him about this, and he said, "The shortest duration of menstruation is one day and night, and the longest is fifteen days."  

الدارمي:٨٧١أَخْبَرَنَا مُحَمَّدُ بْنُ يُوسُفَ قَالَ قَالَ سُفْيَانُ بَلَغَنِي عَنْ أَنَسٍ

أَنَّهُ قَالَ «أَدْنَى الْحَيْضِ ثَلَاثَةُ أَيَّامٍ» سُئِلَ عَبْدُ اللَّهِ الدَّارِمِيُّ تَأْخُذُ بِهَذَا؟ قَالَ «نَعَمْ إِذَا كَانَ عَادَتَهَا» وَسَأَلْتُهُ أَيْضًا عَنْ هَذَا؟ قَالَ «أَقَلُّ الْحَيْضِ يَوْمٌ وَلَيْلَةٌ وَأَكْثَرُهُ خَمْسَ عَشْرَةَ»