First we find the day on 1.3.2005 1.3.2005 = (2004 years + Period from 1.1.2005 to 1.3.2005) Odd days in 1600 years = 0 Odd days in 400 years = 0 4 years = (1 leap year + 3 ordinary years) = (1 × 2 + 3 × 1) odd days = 5 odd days Jan. Feb. March (31 + 28 + 11) = 60 days = (8 weeks + 4 days) ≡ 4 odd days. Total number of odd days = (0 + 0 + 5 + 4) = 9 ≡ 2 odd days ∴ 1.3.2005 was Tuesday. So, Friday lies on 4.3.2005 Hence, Friday lies on 4th, 11th, 18th and 25th of March, 2005.
Explanation as extracted from the printed page; notation may be imperfect.