- year
- An integer from 1 through 9378 that represents the year.
- month
- An integer that represents the month and ranges from 1 through 12 if year is not 9378, or 1 through 10 if year is 9378.
- day
- An integer from 1 through 31 that represents the day.
- era
- An integer from 0 through 1 that represents the era.
true if the specified day is a leap day; otherwise, false.