我需要将数据作为Julian日期发送到大型机。但我不知道如何在Flutter或Dart中做到这一点。有一个插件,但似乎与Dart2不兼容。那么将日期转换为Julian日期的通用版本是什么?
有许多packages可以帮助你,但我个人并不熟悉它们。使用Dart中的DateTime
和Duration
类很容易计算出来,例如:
// Julian day zero started at noon, November 24, 4714 BC
// in the proleptic Gregorian calendar.
// (Since 1 BC is year 0, we use -4713 for the year here)
final julianEpoch = DateTime.utc(-4713, 11, 24, 12, 0, 0);
int julianDayNumber(DateTime date) =>
date.difference(julianEpoch).inDays;
double julianDay(DateTime date) =>
date.difference(julianEpoch).inSeconds / Duration.secondsPerDay;
DateTime dateFromJulianDay(num julianDay) =>
julianEpoch + Duration(milliseconds: (julianDay * Duration.milliSecondsPerDay).floor());
double modifiedJulianDay(DateTime date) => julianDay(date) - 2400000.5;