Which day is 10th October, 2027?

To determine the day of the week for October 10, 2027, we can use the concept of odd days.

1. Find the day for January 1, 2027:

   • We know January 1, 2024, was a Monday.
   • From Jan 1, 2024, to Jan 1, 2025: 2024 is a leap year (366 days = 52 weeks + 2 odd days). So, Jan 1, 2025 = Monday + 2 days = Wednesday.
   • From Jan 1, 2025, to Jan 1, 2026: 2025 is a common year (365 days = 52 weeks + 1 odd day). So, Jan 1, 2026 = Wednesday + 1 day = Thursday.
   • From Jan 1, 2026, to Jan 1, 2027: 2026 is a common year (365 days = 52 weeks + 1 odd day). So, Jan 1, 2027 = Thursday + 1 day = Friday.

2. Calculate odd days from January 1, 2027, to October 10, 2027:

   • January (remaining 30 days from Jan 2 to Jan 31): 30 mod 7 = 2 odd days
   • February (2027 is not a leap year, 28 days): 28 mod 7 = 0 odd days
   • March (31 days): 31 mod 7 = 3 odd days
   • April (30 days): 30 mod 7 = 2 odd days
   • May (31 days): 31 mod 7 = 3 odd days
   • June (30 days): 30 mod 7 = 2 odd days
   • July (31 days): 31 mod 7 = 3 odd days
   • August (31 days): 31 mod 7 = 3 odd days
   • September (30 days): 30 mod 7 = 2 odd days
   • October (first 10 days): 10 mod 7 = 3 odd days

   Total odd days = 2 + 0 + 3 + 2 + 3 + 2 + 3 + 3 + 2 + 3 = 23 odd days. Now, find the remainder when 23 is divided by 7: 23 mod 7 = 2.

3. Add the odd days to the reference day: Starting from Friday (Jan 1, 2027) + 2 odd days = Sunday.

Therefore, October 10, 2027, will be a Sunday.

The final answer is A) Sunday.