caleb

Jewish dates conversion tool

Usage:

go get github.com/simolev/caleb

package main

import (
      "fmt"
      "github.com/simolev/caleb"
      "time"
)

func main() {
      j1 := caleb.JewishDate{Shana: 5779, Chodesh: 7, Yom: 25} // 25 Adar II 5779
      g1 := caleb.JewishToGregorian(j1)                        //
      fmt.Println(j1, "=>", g1.Format("2006-01-02"))           // 25 Adar II 5779 => 2019-04-01
      g2 := time.Date(2018, 8, 11, 0, 0, 0, 0, time.UTC)       // 2018-08-11
      j2 := caleb.GregorianToJewish(g2)                        //
      fmt.Println(g2.Format("2006-01-02"), "=>", j2)           // 2018-08-11 => 30 Av 5778
}

Disclaimer:

a) It is not accurate for dates before Gregorian 1582-10-15. In the Gregorian calendar, there are 10 missing days between 1582-10-15 and 1582-10-04. Those days never occurred, but nonetheless they seem to exist in go's implementation, and the only solution I see at the moment would be to add manual correction to the algorithm.

b) This is quite new and would require more thorough testing before being relied upon.

c) Code could be more idiomatic and optimized.

Credits:

Thanks to info@dafaweek.com.
Converted from javascript: http://www.dafaweek.com/HebCal/HebCalSampleSource.php
See also http://www.dafaweek.com/hebcal/hebcalvb6.php