I’m using ICU4J calendar library for converting dates between calendar systems (Gregorian, Japanese, Chinese, Jalali, Islamic,…).
I use it with normal dates (after ERA) like this :
Calendar gc = new GregorianCalendar();
gc.setTime(dateOBJ);
Is it possible to set before ERA dates (e.g. year 500 BC)?
I has its implementation, I used this: