Arrow: Go Date Parsing

Arrow provides a C style format based parsing in Golang (among other helpful date/time functions).

Time flies like an arrow; fruit flies like a banana.

Strftime Compatability

The problem with formatting times in Golang is that the format string you give is based on re-formatting a single date that is a pain to remember (I know it's 1/2 3:04:05 2006 -0700, but I'm lazy). Most languages based on C (Python, etc) use a string formatting based on strftime, which is what I think most people are familiar with.

So here's strftime compatability for Golang with CFormat and CParse:

package main

import (
	"fmt"

	"github.com/mayowa/arrow"
)

func main() {
     // formatting
     fmt.Println("Current date: ", arrow.Now().CFormat("%Y-%m-%d %H:%M"))

     // parsing
     parsed, _ := arrow.CParse("%Y-%m-%d", "2015-06-03")
     fmt.Println("Some other date: ", parsed)
}

Additional Fun

You can also utilize helpful functions to get things like the beginning of the minute, hour, day, week, month, and year.

day := arrow.Now().AtBeginningOfWeek().CFormat("%Y-%m-%d")
fmt.Println("First day of week: ", day)

hour := arrow.Now().AtBeginningOfHour().CFormat("%Y-%m-%d %H:%M")
fmt.Println("First second of hour: ", hour)

You can also more easily sleep until specific times:

// sleep until the next minute starts
arrow.SleepUntil(arrow.NextMinute())
fmt.Println(arrow.Now().CFormat("%H:%M:%S"))

There are also helpers to get today, yesterday, and UTC times:

day := arrow.Yesterday().CFormat("%Y-%m-%d")
fmt.Println("Yesterday: ", day)

dayutc := arrow.UTC().Yesterday().CFormat("%Y-%m-%d %H:%M")
fmt.Println("Yesterday, UTC: ", dayutc)

newyork := arrow.InTimezone("America/New_York").CFormat("%H:%M:%s")
fmt.Println("Time in New York: ", newyork)

And for generating ranges when you need to iterate:

// Print every minute from now until 24 hours from now
for _, a := range arrow.Now().UpTo(arrow.Tomorrow(), arrow.Minute) {
     fmt.Println(a.CFormat("%Y-%m-%d %H:%M:%S"))
}