32 lines
876 B
JavaScript
32 lines
876 B
JavaScript
module.exports = convert;
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module.exports.toDate = convertToDate;
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module.exports.toJulianDay = toJulianDay;
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module.exports.toMillisecondsInJulianDay = toMillisecondsInJulianDay;
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module.exports.fromJulianDayAndMilliseconds = fromJulianDayAndMilliseconds;
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var DAY = 86400000;
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var HALF_DAY = DAY / 2;
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var UNIX_EPOCH_JULIAN_DATE = 2440587.5;
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var UNIX_EPOCH_JULIAN_DAY = 2440587;
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function convert(date) {
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return (toJulianDay(date) + (toMillisecondsInJulianDay(date) / DAY)).toFixed(6);
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};
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function convertToDate(julian) {
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return new Date((Number(julian) - UNIX_EPOCH_JULIAN_DATE) * DAY);
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};
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function toJulianDay(date) {
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return ~~((+date + HALF_DAY) / DAY) + UNIX_EPOCH_JULIAN_DAY;
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};
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function toMillisecondsInJulianDay(date) {
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return (+date + HALF_DAY) % DAY;
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};
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function fromJulianDayAndMilliseconds(day, ms) {
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return (day - UNIX_EPOCH_JULIAN_DATE) * DAY + ms;
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};
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