golang 时间的比较，time.Time的初始值？

 

// 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)

 

---------------------------------------------------------------

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.

Time instants can be compared using the Before, After, and Equal methods. The Sub method subtracts two instants, producing a Duration. The Add method adds a Time and a Duration, producing a Time.

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, ".")
    }
}