100 yr have 5 odd days.
∴ Last day of 1st century of is Friday.
200 yr have (5 x 2) = 1 week + 3 odd day = 3 odd day
∴ Last day of 2nd century of Wednesday,
300 yr have (5 x 3) = 2 week + 1 odd day = 1 odd day
∴ Last day of 3rd century is Monday.
400 yr have 0 odd day.
∴ Last day of 4th century is Sunday.
This cycle is repeated.
∴ Last day of a century cannot be Tuesday of Thursday of Saturday.
