The Fasting Section · 11 – The Situation of Someone Who Adds Sha'ban to Ramadan
Abu Hurayra, may Allah be pleased with him, narrated:
Do not add to the Ramadhan fast (its beginning) one or two days, but if a person has been observing an oath-bound vow, then let him complete it.
Umm Salamah, may Allah be pleased with her, related:
The Messenger of Allah, peace and blessings be upon him, would not fast any month of the year completely except for Ramadan. He would add Shaban to Ramadan except for Shaban.