Check If a Date/Time Has Been Set with IsZero

// utc life

loc, _ := time.LoadLocation("UTC")

// setup a start and end time

createdAt := time.Now().In(loc).Add(1 * time.Hour)

expiresAt := time.Now().In(loc).Add(4 * time.Hour)

// get the diff

diff := expiresAt.Sub(createdAt)

fmt.Printf("Lifespan is %+v", diff)

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Check If a Date/Time Has Been Set with IsZero

0001-01-01 00:00:00 +0000 UTC

package main

import (

    "fmt"

    "time"

)

func main() {

    var myDate time.Time

    // IsZero returns a bool of whether a date has been set, but as the printf shows it will

    // still print a zero-based date if it hasn't been set.

    if myDate.IsZero() {

        fmt.Printf("No date has been set, %s\n", myDate)

    }

    // Demonstrating that by setting a date, IsZero now returns false

    myDate = time.Date(2019, time.February, 1, 0, 0, 0, 0, time.UTC)

    if !myDate.IsZero() {

        fmt.Printf("A date has been set, %s\n", myDate)

    }

}

Use the time package to work with time information in Go.

Play example:

package main

import (

    "fmt"

    "time"

)

func inTimeSpan(start, end, check time.Time) bool {

    return check.After(start) && check.Before(end)

}

func main() {

    start, _ := time.Parse(time.RFC822, "01 Jan 15 10:00 UTC")

    end, _ := time.Parse(time.RFC822, "01 Jan 16 10:00 UTC")

    in, _ := time.Parse(time.RFC822, "01 Jan 15 20:00 UTC")

    out, _ := time.Parse(time.RFC822, "01 Jan 17 10:00 UTC")

    if inTimeSpan(start, end, in) {

        fmt.Println(in, "is between", start, "and", end, ".")

    }

    if !inTimeSpan(start, end, out) {

        fmt.Println(out, "is not between", start, "and", end, ".")

    }

}