Construct a date out of a year, a month and a day.

Input parameters:

1. Y → Gregorian year, must be between 1 and 9999.
2. M → Gregorian month.
   •  1 → January
   •  2 → February
   •  3 → March
   •  4 → April
   •  5 → May
   •  6 → June
   •  7 → July
   •  8 → August
   •  9 → September
   • 10 → October
   • 11 → November
   • 12 → December
3. D → Day of the month.

Output parameters:

1. D → Constructed date, set to midnight.