Day of the Week

Given a date as three integers — year, month, and day — return the day of the week as a string: "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", or "Saturday".

The date will always be a valid Gregorian calendar date with year >= 1583.

You may use Zeller's congruence or any other algorithm to compute the day. Zeller's congruence works as follows:

1. If month < 3, treat it as month 13 or 14 of the previous year (i.e., add 12 to month, subtract 1 from year)
2. Compute: h = (day + floor(13*(month+1)/5) + k + floor(k/4) + floor(j/4) - 2*j) mod 7
   • Where k = year % 100 and j = floor(year / 100)
3. h maps to: 0=Saturday, 1=Sunday, 2=Monday, 3=Tuesday, 4=Wednesday, 5=Thursday, 6=Friday

Note: Some languages produce negative remainders for the modulo operation. Make sure h is non-negative (e.g., use ((value % 7) + 7) % 7).