addMonths method
Adds a specified number of months to the current DateTime instance.
Example usage:
final date = DateTime(2020, 1, 1);
final newDate = date.addMonths(2);
print(newDate); // 2020-03-01 00:00:00.000
Implementation
DateTime addMonths(int amount) => DateTime(year, month + amount, day, hour, minute, second);