How many odd days are accumulated from 1 January 2025 to 1 January 2030?
Explanation: The interval spans 5 years: 2025, 2026, 2027, 2028, 2029. The only leap year is 2028. Each ordinary year contributes 1 odd day and each leap year contributes 2 odd days. The total equals 4 × 1 + 1 × 2 = 4 + 2 = 6 ≡ 6 (mod 7).
If 1 January 2025 is a Wednesday, what day of the week is 1 December 2025?
- Tuesday
- Sunday
- Saturday
- Monday
Explanation: From January 1 to December 1: January (31) + February (28) + March (31) + April (30) + May (31) + June (30) + July (31) + August (31) + September (30) + October (31) + November (30) = 334 days. Three hundred thirty-four days equals 47 weeks plus 5 odd days. Wednesday + 5 = Monday.
What day of the week was 1 January 2000?
- Sunday
- Friday
- Thursday
- Saturday
Explanation: From 1 January 1900 (Monday) to 1 January 2000 is 100 years. The 20th century contains 24 leap years (1904 through 1996, excluding 1900). The odd days equal 76 × 1 + 24 × 2 = 76 + 48 = 124 ≡ 5 (mod 7). Monday + 5 = Saturday.
What day of the week is 1 January 1896?
- Tuesday
- Wednesday
- Monday
- Thursday
Explanation: From 1 January 1896 to 1 January 1900 is 4 years, containing 1 leap year (1896). The odd days equal 3 ordinary years × 1 + 1 leap year × 2 = 3 + 2 = 5. Going backward 5 days from Monday (1 January 1900): Monday − 5 = Wednesday.
How many leap years are there from 1 January 2001 to 31 December 2100 inclusive?
Explanation: The period 2001-2100 contains 100 years. A year is a leap year if divisible by 4, except if divisible by 100 but not by 400. The leap years are 2004, 2008, ..., 2096 (every 4 years). The year 2100 is divisible by 100 but not by 400, so it is not a leap year. From 2004 to 2096 inclusive: (2096 − 2004) / 4 + 1 = 24 leap years.
The calendar for the year 2023 will next repeat in which year?
Explanation: The year 2023 is not a leap year. For a non-leap year calendar to repeat, the accumulated odd days must be 0 (mod 7), and the target year must also not be a leap year. From 2023 to 2034 is 11 years, containing 3 leap years (2024, 2028, 2032). The odd days equal 8 × 1 + 3 × 2 = 14 ≡ 0 (mod 7). Since 2034 is not a leap year, the calendar repeats exactly.
What day of the week was 1 January 1900?
- Monday
- Wednesday
- Tuesday
- Sunday
Explanation: In calendar calculations, 1 January 1900 serves as the standard reference anchor date for the Gregorian calendar, and it is established as a Monday.
How many Saturdays are there in March 2024?
Explanation: March 2024 has 31 days and begins on a Friday. Thirty-one days equals 4 complete weeks plus 3 extra days (Friday, Saturday, Sunday). Since Saturday appears among these extra days, it occurs 5 times during the month.
If 1 January 2024 is a Monday, what day of the week is 31 January 2024?
- Thursday
- Tuesday
- Wednesday
- Friday
Explanation: From January 1 to January 31 is an interval of 30 days. Thirty days equals 4 weeks plus 2 odd days. Monday + 2 = Wednesday.
If 15 August 2024 is a Thursday, what day of the week was 15 February 2024?
- Tuesday
- Wednesday
- Thursday
- Friday
Explanation: From February 15 to August 15: the remaining 14 days of February + March (31) + April (30) + May (31) + June (30) + July (31) + August (15) = 182 days. One hundred eighty-two days equals exactly 26 weeks with 0 odd days. Therefore, both dates fall on the same day of the week.
If 1 January 2025 is a Wednesday, what day of the week is 1 April 2025?
- Thursday
- Tuesday
- Monday
- Wednesday
Explanation: January has 31 days, February 2025 has 28 days, and March has 31 days. From January 1 to April 1 is 31 + 28 + 31 = 90 days. Ninety days equals 12 weeks plus 6 odd days. Wednesday + 6 = Tuesday.
If 1 January 2024 is a Monday, what day of the week is 31 December 2024?
- Tuesday
- Wednesday
- Sunday
- Monday
Explanation: The year 2024 is a leap year with 366 days total. From January 1 to December 31 is an interval of 365 days. Since 365 ≡ 1 (mod 7), Monday advances by 1 day to Tuesday.
If 15 August 2025 is a Friday, what day of the week was 15 August 1947?
- Friday
- Saturday
- Wednesday
- Thursday
Explanation: From 1947 to 2025 is 78 years. The period contains 20 leap years (1948, 1952, ..., 2024). The total odd days equal 58 ordinary years × 1 + 20 leap years × 2 = 58 + 40 = 98 days. Since 98 is exactly divisible by 7, the two dates fall on the same day of the week.
A library has physical wall calendars from the year 2024. What is the next year when these calendars can be reused without any modification?
Explanation: For a leap year calendar to repeat, two conditions must be met: the target year must also be a leap year, and the accumulated odd days between the two years must be a multiple of 7. From 2024 to 2052 is 28 years, containing 7 leap years and 21 ordinary years. The odd days equal 21 × 1 + 7 × 2 = 35, which is divisible by 7. Since 2052 is a leap year and the interval does not cross a non-leap century year (like 2100), the calendar repeats exactly.
The Constitution of India came into effect on 26 January 1950. What day of the week was it?
- Tuesday
- Friday
- Thursday
- Wednesday
Explanation: Calculate the odd days from the reference date of 1 January 1900 (Monday). From 1900 to 1950 is 50 years with 12 leap years (1904, 1908, ..., 1948). Odd days = 38 × 1 + 12 × 2 = 38 + 24 = 62 ≡ 6 (mod 7). Monday + 6 = Sunday for 1 January 1950. Then from January 1 to January 26 is 25 days ≡ 4 (mod 7). Sunday + 4 = Thursday.
How many times does Friday the 13th occur in the year 2025?
Explanation: Calculate the weekday of the 1st of each month in 2025, then add 12 days (≡ 5 odd days) to find the weekday of the 13th. June 1, 2025 is a Sunday; Sunday + 5 = Friday. This is the only month in 2025 where the 13th falls on a Friday.
How many odd days are accumulated from 1 January 2024 to 1 January 2030?
Explanation: The interval spans 6 years: 2024, 2025, 2026, 2027, 2028, 2029. The leap years are 2024 and 2028. Each ordinary year contributes 1 odd day and each leap year contributes 2 odd days. The total equals 4 × 1 + 2 × 2 = 4 + 4 = 8 ≡ 1 (mod 7).
What day of the week is 15 August 2025?
- Wednesday
- Thursday
- Saturday
- Friday
Explanation: 1 January 2025 is a Wednesday. From January 1 to August 15 is an interval of 226 days (January 30 remaining + February 28 + March 31 + April 30 + May 31 + June 30 + July 31 + August 15). Two hundred twenty-six days equals 32 weeks plus 2 odd days. Wednesday + 2 = Friday.
If 15 August 2025 is a Friday, what day of the week will 15 August 2026 be?
- Thursday
- Sunday
- Saturday
- Friday
Explanation: The year 2026 is not a leap year. From August 15, 2025 to August 15, 2026 spans exactly 365 days = 1 odd day. Friday advances by 1 day to Saturday.
What day of the week is 1 January 2100?
- Wednesday
- Friday
- Saturday
- Thursday
Explanation: From 1 January 2000 (Saturday) to 1 January 2100 is 100 years. The period 2000-2099 contains 25 leap years (2000, 2004, 2008, ..., 2096). The year 2000 is a leap year because it is divisible by 400, while 2100 is not. The odd days equal 75 ordinary years × 1 + 25 leap years × 2 = 75 + 50 = 125 ≡ 6 (mod 7). Saturday + 6 = Friday.
If 1 January 2025 is a Wednesday, what day of the week is 1 March 2025?
- Saturday
- Friday
- Tuesday
- Sunday
Explanation: January has 31 days and February 2025 has 28 days (2025 is not a leap year). From January 1 to March 1 is 31 + 28 = 59 days. Fifty-nine days equals 8 weeks plus 3 odd days. Wednesday + 3 = Saturday.
How many Sundays are there in February 2025?
Explanation: February 2025 has 28 days and begins on a Saturday. Twenty-eight days equals exactly 4 complete weeks with 0 extra days. Therefore, every day of the week occurs exactly 4 times.
The calendar for the year 2025 will next repeat in which year?
Explanation: The year 2025 is not a leap year. For a non-leap year calendar to repeat, the accumulated odd days must be 0 (mod 7). From 2025 to 2031 is 6 years, containing 1 leap year (2028). The odd days equal 5 × 1 + 1 × 2 = 7 ≡ 0 (mod 7). Since 2031 is not a leap year, the calendar repeats exactly.
What day of the week is 26 January 2024?
- Saturday
- Thursday
- Friday
- Wednesday
Explanation: 1 January 2024 is a Monday. From January 1 to January 26 is an interval of 25 days. Twenty-five days equals 3 weeks plus 4 odd days. Monday + 4 = Friday.
If 1 January 2100 is a Friday, what day of the week will 1 January 2101 be?
- Saturday
- Sunday
- Monday
- Friday
Explanation: The year 2100 is divisible by 100 but not by 400, so it is not a leap year in the Gregorian calendar. It has 365 days, which equals 1 odd day. Friday + 1 = Saturday.
February 2024 has 29 days. How many Tuesdays does it contain?
Explanation: February 2024 begins on a Thursday and has 29 days. Twenty-nine days equals 4 complete weeks plus 1 extra day (Thursday). Tuesday falls on February 6, 13, 20, and 27, giving exactly 4 occurrences.
If 1 January 2024 is a Monday, what day of the week is 1 January 2025?
- Tuesday
- Friday
- Wednesday
- Thursday
Explanation: The year 2024 is a leap year. From January 1, 2024 to January 1, 2025 spans 366 days because February 29, 2024 is included in the interval. Three hundred sixty-six days equals 52 weeks plus 2 odd days. Monday + 2 = Wednesday.
If 1 January 2024 is a Monday, what day of the week is 1 April 2024?
- Wednesday
- Tuesday
- Monday
- Sunday
Explanation: January has 31 days, February 2024 has 29 days, and March has 31 days. From January 1 to April 1 is 31 + 29 + 31 = 91 days. Ninety-one days equals exactly 13 weeks with 0 odd days. Monday + 0 = Monday.
What day of the week is 1 January 2028?
- Thursday
- Saturday
- Friday
- Sunday
Explanation: From 1 January 2025 (Wednesday) to 1 January 2028 spans 3 years: 2025, 2026, and 2027, none of which are leap years. Each contributes 1 odd day, for a total of 3 odd days. Wednesday + 3 = Saturday.
If 1 January 2024 is a Monday, what day of the week is 1 December 2024?
- Monday
- Tuesday
- Saturday
- Sunday
Explanation: From January 1 to December 1: January (31) + February (29) + March (31) + April (30) + May (31) + June (30) + July (31) + August (31) + September (30) + October (31) + November (30) = 335 days. Three hundred thirty-five days equals 47 weeks plus 6 odd days. Monday + 6 = Sunday.
If 5 January 2026 is a Monday, what day of the week will 5 January 2027 be?
- Wednesday
- Sunday
- Tuesday
- Monday
Explanation: The year 2026 is not a leap year. From January 5, 2026 to January 5, 2027 spans exactly 365 days, which equals 52 weeks plus 1 odd day. Monday advances by 1 day to Tuesday.
If 1 January 2025 is a Wednesday, what day of the week is 1 January 2026?
- Friday
- Thursday
- Tuesday
- Wednesday
Explanation: The year 2025 is not a leap year. From January 1, 2025 to January 1, 2026 spans exactly 365 days = 1 odd day. Wednesday + 1 = Thursday.
What day of the week is 1 January 2200?
- Friday
- Thursday
- Tuesday
- Wednesday
Explanation: From 1 January 2100 (Friday) to 1 January 2200 is 100 years. The period 2100-2199 contains 24 leap years (2104, 2108, ..., 2196) because 2100 itself is not a leap year. The odd days equal 76 × 1 + 24 × 2 = 124 ≡ 5 (mod 7). Friday + 5 = Wednesday.
If 1 January 2024 is a Monday, what day of the week was 1 January 2023?
- Saturday
- Monday
- Sunday
- Tuesday
Explanation: The year 2023 is not a leap year. Going backward from 1 January 2024 to 1 January 2023 spans 365 days = 1 odd day. Monday minus 1 day = Sunday.
What day of the week is 29 February 2024?
- Saturday
- Wednesday
- Thursday
- Friday
Explanation: February 1, 2024 is a Thursday. The 29th day of February is exactly 28 days after February 1. Since 28 is divisible by 7, the day of the week remains unchanged. Therefore, February 29, 2024 is also a Thursday.
If 1 January 2024 is a Monday, what day of the week is 1 March 2024?
- Wednesday
- Friday
- Saturday
- Thursday
Explanation: January has 31 days and February 2024 has 29 days (2024 is a leap year). From January 1 to March 1 is 31 + 29 = 60 days. Sixty days equals 8 weeks plus 4 odd days. Monday + 4 = Friday.
What day of the week is 1 January 1898?
- Saturday
- Thursday
- Friday
- Sunday
Explanation: From 1 January 1897 (Friday) to 1 January 1898 spans exactly 365 days because 1897 is not a leap year. Three hundred sixty-five days equals 1 odd day. Friday + 1 = Saturday.
The calendar for the year 2026 will next repeat in which year?
Explanation: The year 2026 is not a leap year. From 2026 to 2037 is 11 years, containing 3 leap years (2028, 2032, 2036). The odd days equal 8 × 1 + 3 × 2 = 8 + 6 = 14 ≡ 0 (mod 7). Since 2037 is not a leap year, the calendar repeats exactly.
What day of the week is 2 October 2025?
- Friday
- Tuesday
- Thursday
- Wednesday
Explanation: January 1, 2025 is a Wednesday. From January 1 to October 2: January (31) + February (28) + March (31) + April (30) + May (31) + June (30) + July (31) + August (31) + September (30) + October (2) = 275 days from the start of the year, which is an interval of 274 days from January 1. Two hundred seventy-four days equals 39 weeks plus 1 odd day. Wednesday + 1 = Thursday.
If 1 March 2024 is a Friday, what day of the week will 1 March 2025 be?
- Friday
- Thursday
- Sunday
- Saturday
Explanation: From March 1, 2024 to March 1, 2025 spans exactly 365 days because February 2024 has already passed by March 1. Since 365 days equals 52 weeks plus 1 odd day, Friday advances by 1 day to Saturday.
What day of the week is 2 October 2024?
- Tuesday
- Friday
- Thursday
- Wednesday
Explanation: 1 October 2024 is a Tuesday. The 2nd day of October is exactly 1 day later. Tuesday + 1 = Wednesday.
What day of the week is 1 January 2400?
- Friday
- Saturday
- Sunday
- Thursday
Explanation: The Gregorian calendar repeats every 400 years with 0 odd days. Since 1 January 2000 is a Saturday, adding 400 years (0 odd days) means 1 January 2400 is also a Saturday.
India gained independence on 15 August 1947. What day of the week was it?
- Saturday
- Friday
- Thursday
- Wednesday
Explanation: From 15 August 1947 to 15 August 2025 is 78 years, containing 20 leap years (1948, 1952, ..., 2024). The total odd days equal 58 ordinary years × 1 + 20 leap years × 2 = 58 + 40 = 98 days, which is exactly divisible by 7. Therefore, both dates fall on the same day of the week.
How many Mondays are there in August 2025?
Explanation: August 2025 has 31 days and begins on a Friday. Thirty-one days equals 4 complete weeks plus 3 extra days (Friday, Saturday, Sunday). Since Monday does not appear among these extra days, it occurs exactly 4 times during the month.
How many Sundays are there in January 2026?
Explanation: January 2026 has 31 days and begins on a Thursday. Thirty-one days equals 4 complete weeks plus 3 extra days (Thursday, Friday, Saturday). Sunday falls on 5 January, 12 January, 19 January, and 26 January, giving exactly 4 occurrences.
What day of the week is 15 August 2024?
- Saturday
- Friday
- Wednesday
- Thursday
Explanation: January 1, 2024 is a Monday. From January 1 to August 15: January (31) + February (29) + March (31) + April (30) + May (31) + June (30) + July (31) + August (15) = 228 days from the start of the year, which is an interval of 227 days from January 1. Two hundred twenty-seven days equals 32 weeks plus 3 odd days. Monday + 3 = Thursday.
If 1 January 2024 is a Monday, what day of the week is 1 October 2024?
- Tuesday
- Thursday
- Wednesday
- Monday
Explanation: From January 1 to October 1: January (31) + February (29) + March (31) + April (30) + May (31) + June (30) + July (31) + August (31) + September (30) = 274 days. Two hundred seventy-four days equals 39 weeks plus 1 odd day. Monday + 1 = Tuesday.
If 1 January 2024 is a Monday, what day of the week is 1 January 2030?
- Monday
- Wednesday
- Sunday
- Tuesday
Explanation: From 1 January 2024 to 1 January 2030 spans 6 years with accumulated odd days of 1 (4 ordinary years and 2 leap years: 4 × 1 + 2 × 2 = 8 ≡ 1). Monday + 1 = Tuesday.
The Gregorian calendar is designed to reset its weekday pattern every 400 years. How many odd days are accumulated in one such complete cycle?
Explanation: In 400 years, there are 303 ordinary years and 97 leap years (the 400th year is a leap year despite being divisible by 100, because it is also divisible by 400). The total days equal 303 × 365 + 97 × 366 = 146097. Dividing by 7 gives 20871 complete weeks with 0 remainder. Therefore, the cycle contains 0 odd days.
If 1 January 2025 is a Wednesday, what day of the week is 1 January 2030?
- Thursday
- Wednesday
- Monday
- Tuesday
Explanation: From 1 January 2025 to 1 January 2030 spans 5 years with accumulated odd days of 6 (4 ordinary years and 1 leap year: 4 × 1 + 1 × 2 = 6). Wednesday + 6 = Tuesday.
If 1 March 2024 is a Friday, what day of the week was 1 February 2024?
- Thursday
- Saturday
- Wednesday
- Tuesday
Explanation: February 2024 has 29 days. From February 1 to March 1 is 29 days. Twenty-nine days equals 4 weeks plus 1 odd day. Going backward from March 1 (Friday): Friday − 1 = Thursday.
What day of the week is 31 December 1899?
- Saturday
- Sunday
- Monday
- Tuesday
Explanation: The year 1899 is not a leap year. From January 1, 1899 (Sunday) to December 31, 1899 is an interval of 364 days. Since 364 = 52 × 7, there are 0 odd days, so the day of the week remains Sunday.
If 1 January 2025 is a Wednesday, what day of the week was 1 January 2024?
- Tuesday
- Thursday
- Sunday
- Monday
Explanation: The year 2024 is a leap year. Going backward from 1 January 2025 to 1 January 2024 spans 366 days because February 29, 2024 is included in the interval. Three hundred sixty-six days equals 52 weeks plus 2 odd days. Wednesday − 2 = Monday.
What day of the week is 1 January 1899?
- Sunday
- Monday
- Saturday
- Friday
Explanation: From 1 January 1898 (Saturday) to 1 January 1899 spans exactly 365 days because 1898 is not a leap year. Three hundred sixty-five days equals 1 odd day. Saturday + 1 = Sunday.
If 1 January 2025 is a Wednesday, what day of the week is 1 January 2028?
- Friday
- Sunday
- Monday
- Saturday
Explanation: From 1 January 2025 to 1 January 2028 spans three years: 2025, 2026, and 2027. None of these are leap years, so each contributes 1 odd day, for a total of 3 odd days. Wednesday + 3 = Saturday.
The calendar for the year 2028 will next repeat in which year?
Explanation: The year 2028 is a leap year. For a leap year calendar to repeat, the target year must also be a leap year and the accumulated odd days must be a multiple of 7. From 2028 to 2056 is 28 years, containing 7 leap years and 21 ordinary years. The odd days equal 21 × 1 + 7 × 2 = 35, which is divisible by 7. Since 2056 is a leap year and the interval does not cross a non-leap century year, the calendar repeats exactly.
If 1 January 2025 is a Wednesday, what day of the week is 1 October 2025?
- Thursday
- Wednesday
- Tuesday
- Friday
Explanation: From January 1 to October 1: January (31) + February (28) + March (31) + April (30) + May (31) + June (30) + July (31) + August (31) + September (30) = 273 days. Two hundred seventy-three days equals exactly 39 weeks with 0 odd days. Wednesday + 0 = Wednesday.
What day of the week is 1 January 2300?
- Sunday
- Tuesday
- Monday
- Saturday
Explanation: From 1 January 2200 (Wednesday) to 1 January 2300 is 100 years. The period 2200-2299 contains 24 leap years. The odd days equal 76 × 1 + 24 × 2 = 124 ≡ 5 (mod 7). Wednesday + 5 = Monday.
If 26 January 2026 is a Monday, what day of the week was 26 January 2025?
- Sunday
- Saturday
- Tuesday
- Friday
Explanation: The year 2025 is not a leap year. Going backward from January 26, 2026 to January 26, 2025 spans 365 days = 1 odd day. Monday minus 1 day = Sunday.
What day of the week is 1 January 1897?
- Wednesday
- Saturday
- Friday
- Thursday
Explanation: The year 1896 is a leap year. From 1 January 1896 (Wednesday) to 1 January 1897 spans 366 days because February 29, 1896 is included. Three hundred sixty-six days equals 52 weeks plus 2 odd days. Wednesday + 2 = Friday.