Fix upgrade path of modify time

command/helpers.go

@@ -94,7 +94,7 @@ func fmtInt(buf []byte, v uint64) int {
 // is 10 months, 12 days, 3 hours and 2 seconds, the string "10mo12d" is returned. Zero values return the empty string
 func prettyTimeDiff(first, second time.Time) string {
 	// handle zero values
-	if first.IsZero() {
+	if first.IsZero() || first.UnixNano() == 0 {
 		return ""
 	}
 	// round to the nearest second

command/helpers_test.go

@@ -302,6 +302,8 @@ func TestPrettyTimeDiff(t *testing.T) {
 		t2  time.Time
 		exp string
 	}{
+		{now, time.Unix(0, 0), ""}, // This is the upgrade path case
+		{now, now.Add(-10 * time.Millisecond), "0s ago"},
 		{now, now.Add(-10 * time.Millisecond), "0s ago"},
 		{now, now.Add(-740 * time.Second), "12m20s ago"},
 		{now, now.Add(-12 * time.Minute), "12m ago"},