Question 1

How does the calculator determine the day of the week?

Accepted Answer

The calculator uses Zeller's algorithm or similar methods to mathematically compute the day of the week based on the day, month, and year.

Question 2

Can I find the day for very old dates?

Accepted Answer

Yes, but note that the current Gregorian calendar started in 1582, and dates before that followed the Julian calendar.

Question 3

What is the week number of the year?

Accepted Answer

It is the ordinal number of the week in the year from 1 to 52 or 53, commonly used in business and planning.

Day of Week Calculator