CalendarGregorianToJD converts a Gregorian year, month, and day of month to Julian day.

CalendarJulianToJD converts a Julian year, month, and day of month to Julian day.

DayOfWeek determines the day of the week for a given JD.

DayOfYear computes the day number within the year.

DayOfYearGregorian computes the day number within the year of the Gregorian calendar.

DayOfYearJulian computes the day number within the year of the Julian calendar.

DayOfYearToCalendar returns the calendar month and day for a given day of year and leap year status.

JDToCalendar returns the calendar date for the given jd.

JDToTime takes a JD and returns a Go time.Time value.

LeapYearGregorian returns true if year y in the Gregorian calendar is a leap year.

LeapYearJulian returns true if year y in the Julian calendar is a leap year.

TimeToJD takes a Go time.Time and returns a JD as float64.