# convertToGregorianDate function Null safety

DateTime convertToGregorianDate(
1. date,
2. {int year = 0,
3. int month = 0,
4. int day = 0}
)

Converts and returns the gregorian date from the given hijri date values.

## Implementation

``````DateTime convertToGregorianDate(HijriDateTime? date,
{int year = 0, int month = 0, int day = 0}) {
if (date != null) {
return date._date;
}

assert(year != 0);
assert(month != 0);
assert(day != 0);

/// When the year exceeds the maximum year limit return the maximum value.
if (year > 1500) {
return DateTime(2077, 11, 16);
} else if (year < 1356) {
/// Return minimum hijri date equivalent gregorian date value when
/// hijri year value before the minimum year value.
return DateTime(1937, 03, 14);
}

final int iy = year;
final int im = month;
final int id = day;
final int ii = iy - 1;
final int iln = (ii * 12) + 1 + (im - 1);
final int i = iln - 16260;
final int mcjdn = id + _kDateCollection[i - 1] - 1;
final int julianDate = mcjdn + 2400000;
final int z = (julianDate + 0.5).floor();
int a = ((z - 1867216.25) / 36524.25).floor();
a = z + 1 + a - (a / 4).floor();
final int b = a + 1524;
final int c = ((b - 122.1) / 365.25).floor();
final int d = (365.25 * c).floor();
final int e = ((b - d) / 30.6001).floor();
final int gDay = b - d - (e * 30.6001).floor();
int gMonth = e - (e > 13.5 ? 13 : 1);
final int gYear = c - (gMonth > 2.5 ? 4716 : 4715);
/* istanbul ignore next */
if (gYear <= 0) {
gMonth--;
} // No year zero
return DateTime(gYear, gMonth, gDay);
}``````