Reference: Sharh ‘Umdatil-Fiqh – Tape No.6, Question No.54
Question: What is the ruling of taking a bath [or shower] on the day of Jumu’ah, and when is it’s time?
Response: Taking a bath [or shower] on the day of Jumu’ah is a highly recommended Sunnah, and it’s time begins with the start of the day, on the day of Jumu’ah.