[Ghost]

bad3p
Пришлось малехо помучиться

uses
  crt;

type
  years  = 0..2100;
  months = 1..12;
  days   = 1..31;

const
  day_months: array [months] of days =
    (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
  day_weeks:  array [0..6] of string =
    ('VOS', 'PN', 'VT', 'SRE', 'CHE', 'PIA', 'SUB');

var
  year:  years;
  month: months;
  day:   days;
  feb29: boolean;
  alld:  longint;
  i:     integer;

begin
  clrscr;
  write ('year  (0-2100): '); readln(year);
  write ('month (1-12):   '); readln(month);
  feb29 := ((year mod 4) = 0);
  if ((year mod 100) = 0) then feb29 := ((year mod 400) <> 0);
  if feb29 then day_months[2] := 29 else day_months[2] := 28;
  repeat
    write ('day   (1-', day_months[month], '):   '); readln(day);
  until (day > 0) and (day <= day_months[month]);
  alld := year + (year div 4) - 3;
  for i := 1 to pred(month) do inc (alld, day_months[i]);
  alld := (alld + day) mod 7;
  writeln('day of week:    ', day_weeks[alld]);
  readkey;
end.