diff --git a/btrbk b/btrbk
index 6c7c434..51f12f7 100755
--- a/btrbk
+++ b/btrbk
@@ -3064,7 +3064,7 @@ MAIN:
           # find unique snapshot name
           my $timestamp = ((config_key($config_subvol, "timestamp_format") eq "short") ?
                            sprintf("%04d%02d%02d", @today) :
-                           sprintf("%04d%02d%02dT%02d%02d", @today_and_now));
+                           sprintf("%04d%02d%02dT%02d%02d", @today_and_now[0..4]));
           my @unconfirmed_target_name;
           my @lookup = keys %{vinfo_subvol_list($sroot)};
           @lookup = grep s/^\Q$snapdir\E// , @lookup;