cmd/tier: accept --at flag for report (#304)

cmd/tier/help.go

@@ -183,6 +183,10 @@ Flags:
     --clobber
 	Clobber any existing usage for the provided feature. If false, the
 	usage will be incremeneted by n.
+    --at
+	At specifies the time at which the usage occurred. If not provided,
+	the current time will be used. The time must be in seconds since the
+	epoch.
 `,
 	"whois": `Usage:
 

cmd/tier/tier.go

@@ -402,6 +402,7 @@ func runTier(cmd string, args []string) (err error) {
 	case "report":
 		fs := flag.NewFlagSet(cmd, flag.ExitOnError)
 		clobber := fs.Bool("clobber", false, "clobber existing value")
+		fat := fs.String("at", "", "sets the time of the usage event (unix seconds)")
 		if err := fs.Parse(args); err != nil {
 			return err
 		}
@@ -417,7 +418,16 @@ func runTier(cmd string, args []string) (err error) {
 		if err != nil {
 			return err
 		}
+		var at time.Time
+		if *fat != "" {
+			nsecs, err := strconv.ParseInt(*fat, 10, 64)
+			if err != nil {
+				return err
+			}
+			at = time.Unix(nsecs, 0)
+		}
 		return tc().ReportUsage(ctx, org, feature, n, &tier.ReportParams{
+			At:      at,
 			Clobber: *clobber,
 		})
 	case "whoami":