Hadithcore
Hadith #2105320

The narration of Abu Dawud from 'Imran bin Husain (RA) has:

"eighteen days."

وَلَهُ عَنْ عِمْرَانَ بْنِ حُصَيْنٍ: { ثَمَانِيَ عَشْرَةَ } [1]‏ .‏

References2 variants
Sunnah.com reference
Book 2, Hadith 348
Arabic/English book reference
Book 2, Hadith 431