openhours

golang implementation of opening hours (inspired by OpenStreetMap opening hours: http://wiki.openstreetmap.org/wiki/Key:opening_hours)

This Go library let you define time intervals in human-readable form and then check if specified time matches this interval.

Install

Run go get github.com/yauhen-l/openhours

Usage

package main

import (
    "fmt"
    "time"

    "github.com/yauhen-l/openhours"
)

func main() {
	oh, errs := openhours.CompileOpenHours("Mo-We 06:00-17:00")
	if len(errs) > 0 {
	  fmt.Printf("%v\n", errs)
	  return
	}

	// Simple check if currently open
	fmt.Println("Currently open:", oh.Match(time.Now()))

	// Get detailed status information
	isOpen, nextChange, duration := oh.MatchExt(time.Now())
	if isOpen {
		fmt.Printf("Open! Will close at %v (in %v)\n",
			nextChange.Format("15:04"), duration)
	} else {
		if nextChange.IsZero() {
			fmt.Println("Closed (never opens)")
		} else {
			fmt.Printf("Closed. Will open at %v (in %v)\n",
				nextChange.Format("Mon 15:04"), duration)
		}
	}
}

API Reference

Match(time.Time) bool

Returns true if the location is open at the given time, false otherwise.

MatchExt(time.Time) (isOpen bool, nextChange time.Time, duration time.Duration)

Returns detailed status information:

• isOpen: whether currently open
• nextChange: when status will next change (zero time if never changes, e.g., for "24/7")
• duration: how long until the status change

// Business hours example
oh, _ := openhours.CompileOpenHours("Mo-Fr 09:00-17:00")

// Tuesday 2 PM
isOpen, nextChange, duration := oh.MatchExt(time.Date(2023, 6, 13, 14, 0, 0, 0, time.UTC))
// isOpen: true
// nextChange: Tuesday 17:00
// duration: 3h0m0s

// Tuesday 8 PM
isOpen, nextChange, duration = oh.MatchExt(time.Date(2023, 6, 13, 20, 0, 0, 0, time.UTC))
// isOpen: false
// nextChange: Wednesday 09:00
// duration: 13h0m0s

Examples

OpenHours simplified pattern:

OpenHours = (days(,days)*)? (MMM)? (Wds(,Wds)*)? (timespan(,timespans)*)?

days = day | day-day       #Days of month
Wds = Wd | Wd-Wd           #Weekdays
timespan = hh:mm-hh:mm     #Day time range

Openhours	Description
24/7	Matches everything
24 Dec	Any time on 24th of December
01-05	Any time from 1st till 5th of any month
18:00-18:30	Any day from 6PM till 6:30PM
Sa,Su 10:00-22:00	From 10AM till 10PM on Saturday and Sunday
Mo; Tu 9:00-15:00	Any time on Monday and from 9AM till 3PM on Tuesday

OpenStreetMap Specification Compatibility

This table shows which features from the OpenStreetMap opening_hours specification are currently supported:

Feature	Status	Examples	Notes
Time Formats
Basic 24-hour (HH:MM)	✅	08:00-17:00	Fully supported
Multiple time intervals	✅	08:00-12:00,13:00-17:00	Comma-separated
Time validation	✅	Hours 0-24, minutes 0-59	Full validation
24:00+ format	❌	18:00-26:00	Not supported
Open-ended times	❌	18:00+	Not supported
Variable times	❌	sunrise-sunset	Not supported
Weekdays
Individual weekdays	✅	Mo, Tu, We, Th, Fr, Sa, Su	All supported
Weekday ranges	✅	Mo-Fr, Sa-Su	Fully supported
Multiple weekdays	✅	Mo,We,Fr	Comma-separated
Nth occurrence	❌	Su[1] (first Sunday)	Not supported
Dates and Months
Day of month	✅	20 (20th of any month)	Fully supported
Day ranges	✅	01-05, 20-25	Fully supported
Month names	✅	Jan, Feb, Mar, etc.	All abbreviations
Day with month	✅	20 Mar, 24 Dec	Fully supported
Specific years	❌	2024 Jan 10	Not supported
Week numbers	❌	week 25	Not supported
Special Values
Always open	✅	24/7	Fully supported
Public holidays	❌	PH, PH off	Not supported
School holidays	❌	SH	Not supported
Closed/off status	❌	off, closed	Not supported
Complex Rules
Semicolon separator	✅	Mo 10:00-12:00; Tu 14:00-16:00	Overwriting rules
Combined patterns	✅	20,21 Mar Mo	Day+month+weekday
Comments	❌	"children only"	Not supported
Colon separator	❌	Dec 25: 08:30-20:00	Not supported
Fallback rules	❌	Mo-Fr 08:00-18:00 || "by appointment"	Not supported

Coverage Summary:

• ✅ Basic features: ~70% - Covers most common use cases
• ❌ Advanced features: ~20% - Missing complex rules and special cases

This implementation focuses on the most commonly used opening hours patterns and provides a solid foundation for typical business hour specifications.

Contribution

If want to extend syntax then you need to install few more packages:

// Lexer
go install github.com/blynn/nex
// Parser
go install github.com/cznic/goyacc

And make sure that both nex and goyacc are in the path

To verify changes:

go generate && go test -v