checktiming.go

package main

import (
	"fmt"
	"log"
	"time"
)

// func Date(year int, month Month, day, hour, min, sec, nsec int, loc *Location) Time

func main() {
	d, _ := time.ParseDuration("3h15s")

	todayYear := time.Now().Year()
	todayMonth := time.Now().Month()
	todayDay := time.Now().Day()

	loc, _ := time.LoadLocation("Asia/Singapore")

	fmt.Printf("Three hours before now: %v", time.Now().In(loc).Add(-d))
	openingTime := time.Date(todayYear, todayMonth, todayDay, 9, 0, 0, 0, loc)
	closingTime := time.Date(todayYear, todayMonth, todayDay, 18, 0, 0, 0, loc)
	now := time.Now().In(loc)
	bookingTime, _ := time.ParseInLocation("2006-01-02 15:04", "2018-08-22 05:57", loc)
	timeBeforeBooking := bookingTime.Sub(now)
	bookingBuffer, _ := time.ParseDuration("3h15s")
	log.Println(timeBeforeBooking, bookingTime, openingTime, closingTime, now, time.Now().In(loc))
	switch {
	case bookingTime.Before(now):
		log.Println("failed: attempt to time travel")
	case bookingTime.Before(openingTime):
		log.Println("before opening time")
	case bookingTime.After(closingTime):
		log.Println("after closing time")
	case timeBeforeBooking < bookingBuffer:
		log.Println("please book more than 3 hours in advance.")
	default:
		log.Println("nil")
	}
}