go-fast-date

3-6x faster than time, see Benchmarks

Go port of A Very Fast 64–Bit Date Algorithm, based on A Very Fast 64–Bit Date Algorithm: 30–40% faster by Ben Joffe. Also uses Parts of The Julian Map: A Faster technique for Gregorian Date Conversion, see Improvements to the Inverse Function. Special thanks to @benjoffe for writing such easy to follow blog posts and implementations.

Usage

go get github.com/xnacly/go-fast-date

package main

import (
	"fmt"
	"time"

	"github.com/xnacly/go-fast-date"
)

func main() {
	date := gofastdate.FromUnix(time.Now().Unix())
	fmt.Println(date)

	fmt.Println(date.Time())
	fmt.Println(date.Unix(), date.Time().Unix())
}

Features

go-fast-date implements Ben Joffe's very fast 64-bit date algorithm and provides date round trip functions for time.Time compatibility:

• gofastdate.FromUnix
• gofastdate.FromTime
• gofastdate.Date.Time
• gofastdate.Date.Unix

While not depending on any dependency and striving to match Joffe's implementation, where applicable.

Benchmarks

kind	benchmark	time	go-fast-date	speedup	runtime reduction
micro	BenchmarkDateToUnix	194.6 ns/op	63.59 ns/op	3.06x	−67.3%
	BenchmarkUnixToDate	582.9 ns/op	90.23 ns/op	6.46x	−84.5%
stress	BenchmarkStressDateToUnix	8.697 ms/op	2.856 ms/op	3.05x	−67.2%
	BenchmarkStressUnixToDate	27.316 ms/op	4.286 ms/op	6.37x	−84.3%

Benchmarks focus on comparing gofastdate.FromUnix with time.Unix. Run with go test ./... -bench=.

goos: linux
goarch: amd64
pkg: github.com/xnacly/go-fast-date
cpu: AMD Ryzen 7 PRO 7840U w/ Radeon 780M Graphics
BenchmarkTimeDateToUnix-16                       6215389               194.6 ns/op             0 B/op          0 allocs/op
BenchmarkGoFastDateToUnix-16                    18198014                63.59 ns/op            0 B/op          0 allocs/op
BenchmarkTimeUnixToDate-16                       2046949               582.9 ns/op             0 B/op          0 allocs/op
BenchmarkGoFastDateFromUnix-16                  12165228                90.23 ns/op            0 B/op          0 allocs/op
BenchmarkStressTimeDateToUnix-16                     135           8696891 ns/op               0 B/op          0 allocs/op
BenchmarkStressGoFastDateToUnix-16                   391           2855936 ns/op               0 B/op          0 allocs/op
BenchmarkStressTimeUnixToDate-16                      37          27315987 ns/op               0 B/op          0 allocs/op
BenchmarkStressGoFastDateFromUnix-16                 282           4285671 ns/op               0 B/op          0 allocs/op
PASS
ok      github.com/xnacly/go-fast-date  13.927s