Ibn Sirin محمد بن سيرين الأنصاري · The Book of Fasting

"One of us (women) would miss some fasts in Ramadan and she would not be able to make it up until Shaban began, and the Messenger of Allah did not fast in any month as he fasted in Shaban; he used to fast all of it, except a little, he used to fast all of it." '