Calendars

After 63 days it will be Monday so after 61 days it will be Saturday

Step 1: 23+90 = 113 Step2: 90/4 Quotient = 22 Step3: add quotient to step 1 113+22+6 (month code) + 0 (year code) Step4: Divide result of step 3 by 7 141/7 Step5: remainder of step 4 is the day code 1------- Monday

For Non-Leap year, When we proceed forward by one year, then 1 day is gained and vice-versa.
If 4th April, 1988 = Monday, then 4th April, 1989 = Tuesday (Because 1989 is a non-leap year)
Remaining days until 5th Nov.89
=Tuesday + 215

The year 2016 is the leap year which has 366 days i.e. 52 weeks and 2 more days. After each week, the day starts repetition. So the day on January 1, 2017 will be 2 days beyond Friday. That is Sunday.

The number of days left after dividing the period by 7 is known as odd days. Every ordinary year has 365 days i.e. 52 weeks and 1 odd day and every leap year has 366 days i.e. 52 weeks and 2 odd days. Every 4th year and every 4th century is the leap year. 100 years have 76 ordinary years and 24 leap years i.e. 76 + 2*24 = 124 odd days. = 7*17 + 5 = 5 odd days. 200 years have = 10 odd days = 7*1 + 3 = 3 odd days. 300 years have = 15 odd days = 1 odd days. Since every 400th year is the leap year, 400 years have = 20 + 1 = 21 odd days = 0 odd days. 1947 years = 1600 years + 300 years + 47 years = 0 odd days + 1 odd day + (11*2 + 36) odd days = 59 odd days = 3 odd days. 30 days have 2 odd days. The total number of odd days up to 30th January 1948 = 5 odd days. Hence, it was a Friday.

The number of days left after dividing the period by 7 is known as odd days. Every ordinary year has 365 days i.e. 52 weeks and 1 odd day and every leap year has 366 days i.e. 52 weeks and 2 odd days. Every 4th year and every 4th century is the leap year. 100 years have 76 ordinary years and 24 leap years i.e. 76 + 2*24 = 124 odd days. = 7*17 + 5 = 5 odd days. 200 years have = 10 odd days = 7*1 + 3 = 3 odd days. 300 years have = 15 odd days = 1 odd days. Since every 400th year is the leap year, 400 years have = 20 + 1 = 21 odd days = 0 odd days. There are 0 odd days in 2000 years. Hence, there is 1 odd day up to the date January 1, 2001. Hence, it was a Monday.