add time command

main.go

@@ -9,8 +9,9 @@ func commandsUsage() string {
 	return fmt.Sprintf(
 		`commands:
   path        %v
+  time        %v
   week        %v
-`, commandPathDescription, commandWeekDescription)
+`, commandPathDescription, commandTimeDescription, commandWeekDescription)
 }
 
 func main() {
@@ -18,6 +19,8 @@ func main() {
 		switch os.Args[1] {
 		case "path":
 			commandPath(os.Args[1:])
+		case "time":
+			commandTime(os.Args[1:])
 		case "week":
 			commandWeek(os.Args[1:])
 		default:

time.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"time"
+)
+
+var commandTimeDescription = "display more information about target timestamp/time"
+
+func commandTime(args []string) {
+	var err error
+	targetTime := time.Now()
+	if len(args) > 1 {
+		targetTime, err = time.Parse(time.RFC3339, args[1])
+		if err == nil {
+			goto GOTTIME
+		}
+		if len(args[1]) <= 10 {
+			var unix int
+			unix, err = strconv.Atoi(args[1])
+			if err != nil {
+				fmt.Printf("`%v` is not a Unix Epoch Time\n", args[1])
+				os.Exit(1)
+			}
+			targetTime = time.Unix(int64(unix), 0)
+		} else if len(args[1]) >= 13 {
+			var unixMilli int
+			unixMilli, err = strconv.Atoi(args[1])
+			if err != nil {
+				fmt.Printf("`%v` is not a Unix Epoch Time in milliseconds\n", args[1])
+				os.Exit(1)
+			}
+			targetTime = time.UnixMilli(int64(unixMilli))
+		} else {
+			fmt.Printf("`%v` is neighter a Unix Epoch Time, nor a formatted time in ISO8601", args[1])
+			os.Exit(1)
+		}
+
+	}
+GOTTIME:
+	fmt.Printf("Unix:               %v\n", targetTime.Unix())
+	fmt.Printf("Unix milliseconds:  %v\n", targetTime.UnixMilli())
+	fmt.Printf("Local time:         %v\n", targetTime.Local().Format(time.RFC3339))
+	fmt.Printf("UTC time:           %v\n", targetTime.UTC().Format(time.RFC3339))
+	fmt.Printf("Time to target:     %v\n", targetTime.Sub(time.Now()))
+}