Convert a Julian-Day number to a time in julian centuries since noon on January 1, 1900. The method follows reference 1 equation 15.1. The example reproduces the example provided by reference 1 example 15.a, with fractional error 3e-8.

julianCenturyAnomaly(jd)

Arguments

jd

a julian day number, e.g. as given by julianDay().

Value

Julian century since noon on January 1, 1900.

References

  1. Meeus, Jean, 1982. Astronomical formulae for Calculators. Willmann-Bell. Richmond VA, USA. 201 pages

See also

Examples

t <- ISOdatetime(1978, 11, 13, 4, 35, 0, tz="UTC") jca <- julianCenturyAnomaly(julianDay(t)) cat(format(t), "is Julian Century anomaly", format(jca, digits=8), "\n")
#> 1978-11-13 04:35:00 is Julian Century anomaly 0.78865684