On 23rd Apr, 2001 it was Monday. What was the day of the week on 23rd Apr, 2000?
Sunday
The year 2000 is a leap year. It has 2 odd days. But it is after Feb, so only 1 odd day will be considered.
∴ The day on 23rd Apr, 2000 is 1 day before the day on 23rd Feb, 2001.
Hence, this day is Sunday.