Question

What day of the week was 20th June 1837?

Answer 1

20th June 1837 means "1836 complete years 1837 + 20 day of June"
1600 years give no odd day
200 years 3 odd days
36 years (27 + 9) 3 odd days
1836 years give 6 odd days
odd days
January = 3
February = 0
March = 3
April = 2
May = 3
June = 6
$\therefore$ Total number of odd days = (6 + 3) or 2
17 i.e. 3 odd days
This means that the 20th June fell on the 2nd day commencing from Monday Therefore the required day was Tuesday