Unix Timestamp in Go

package main

import (
    "fmt"
    "time"
)

func main() {
    now := time.Now()

    fmt.Println(now.Unix())          // seconds:      1700000000
    fmt.Println(now.UnixMilli())     // milliseconds: 1700000000000
    fmt.Println(now.UnixMicro())     // microseconds
    fmt.Println(now.UnixNano())      // nanoseconds
}

// From seconds
t := time.Unix(1700000000, 0)
fmt.Println(t.UTC())                 // 2023-11-14 22:13:20 +0000 UTC

// From milliseconds
ms := int64(1700000000000)
t = time.UnixMilli(ms)

// From nanoseconds
ns := int64(1700000000000000000)
t = time.Unix(0, ns)

t, _ := time.Parse(time.RFC3339, "2023-11-14T22:13:20Z")

fmt.Println(t.Unix())                // 1700000000
fmt.Println(t.UnixMilli())           // 1700000000000

t := time.Unix(1700000000, 0).UTC()

// Go uses a reference time: Mon Jan 2 15:04:05 MST 2006
t.Format(time.RFC3339)               // "2023-11-14T22:13:20Z"
t.Format(time.RFC1123)               // "Tue, 14 Nov 2023 22:13:20 UTC"
t.Format("2006-01-02 15:04:05")      // "2023-11-14 22:13:20"
t.Format("02/01/2006")               // "14/11/2023"

t := time.Unix(1700000000, 0)

// Convert to a specific timezone
loc, _ := time.LoadLocation("Asia/Kolkata")
tIST := t.In(loc)
fmt.Println(tIST.Format("2006-01-02 15:04:05 MST"))  // 2023-11-15 03:43:20 IST

loc2, _ := time.LoadLocation("America/New_York")
fmt.Println(t.In(loc2).Format(time.RFC3339))          // 2023-11-14T17:13:20-05:00

now := time.Now()

future := now.Add(24 * time.Hour)          // 1 day later
past   := now.Add(-7 * 24 * time.Hour)    // 7 days ago

// Duration between two times
diff := future.Sub(past)
fmt.Println(diff.Hours())                  // 192

// Check if expired
expiry := time.Unix(1700000000, 0)
if time.Now().After(expiry) {
    fmt.Println("expired")
}