diff --git a/bin/ssa-retime b/bin/ssa-retime
index 4f97422..38f4b76 100755
--- a/bin/ssa-retime
+++ b/bin/ssa-retime
@@ -7,6 +7,9 @@ use utf8;
 
 use Getopt::Long;
 use Subtitle::Format::SSA;
+use Subtitle::TimePoint;
+
+my @points;
 
 sub usage {
   my ($msg) = @_;
@@ -15,9 +18,9 @@ sub usage {
 Usage: ssa-retime <mode> [<options>] -i <file> [ -o <file>]
 
 Modes are:
-  * framerate       Retime whole file from one fps to another.
-  * points          Retime file specifying point(s) & time shift for it.
-  * shift           Shift whole file or it's part for given time.
+  * framerate       Recalculate timing for different fps
+  * shift           Shift timing in given points
+  * drift           Adjust timing of whole file by time points
 
 Common options:
   -h                This help.
@@ -25,83 +28,77 @@ Common options:
   -o <file>         Output file. Default: write to stdout.
   -v                Be verbose.
 
-Specific options for 'shift' mode:
-  -S <string>       Retime only events with specified style.
-                    This option may be given more than once.
-  -s <time>         Start time of period, that will be changed.
-                    Default: first event.
-  -e <time>         End time of period, that will be changed.
-                    Default: the latest time found in file.
-  -l <time>         Duration of period above. This option require '-s'
-                    You may select either '-o' or '-e' at the same time.
-  -t <time>         Change time for this value.
-
 Specific options for 'framerate' mode:
   -f <float>        Source framerate. Default: 25.0 fps.
   -F <float>        Target framerate.
 
-Specific options for 'points' mode:
+Specific options for 'shift' mode:
+  -m <mode>         How to apply shift by points:
+                    * seq -- apply timeshifts one by one to end of file (default)
+                    * rst -- every next point overrides previous
+  -p <time>/<time>  Point of fixup & time shift in it. Option can be
+                    specified more than once. (see man for details)
+                    Both args must be in form [+-][[h:]m:]s[.ms]
+
+Specific options for 'drift' mode:
   -p <time>/<time>  Point of fixup & time shift in it. Option can be
                     specified more than once. (see man for details)
-                    Both args must be in form of [-][[h:]m:]s[.ms].
+                    Both args must be in form [+-][[h:]m:]s[.ms]
 USAGE
   exit 1;
 }
 
+sub add_point {
+  my ($opt, $val) = @_;
+  my $p = Subtitle::TimePoint->new;
+  my $err = $p->parse($val);
+  die "$err\n" if $err;
+  push @points, $p;
+}
+
 ########### init ###################
 $| = 1;
 
+unless (@ARGV and $ARGV[0] =~ m{^(framerate|shift|drift)$}oi) {
+  usage("You should set mode by first arg");
+}
 my $mode = shift @ARGV;
 
-my @points;
-my %opts = ( loglevel => 0, inrate => 25.0 );
-#GetOptions("qvhi:o:S:f:F:p:t:s:e:l:", \%opts)
+my %opts = ( loglevel => 0, inrate => 25.0, amode => 'seq');
 GetOptions(
   'h|help'        => \&usage,
   'v|verbose+'    => \$opts{loglevel},
   'i|infile=s'    => \$opts{infile},
   'o|outfile=s'   => \$opts{outfile},
 
-  'S|style=s'     => \$opts{style},
-  's|shiftstart=s'=> \$opts{shiftstart},
-  'e|shiftend=s'  => \$opts{shiftend},
-  'l|shiftlen=f'  => \$opts{shiftlen},
-
-  't|shifttime=f' => \$opts{shifttime},
+  'm|amode=s'     => \$opts{amode},
 
   'f|inrate=f'    => \$opts{inrate},
   'F|outrate=f'   => \$opts{outrate},
 
-  'p|point'       => \@points,
+  'p|point=s'     => \&add_point,
 );
 
-($opts{infile} and -f $opts{infile})
-  or usage("Input file not exists");
-
 if ($mode eq 'framerate') {
   $opts{outrate}
-    or usage("You should set at least '-F' option in this mode");
+    or die "You should set '-F' option in this mode\n";
   ($opts{inrate} != 0.0 and $opts{outrate} != 0.0)
-    or usage("Framerate can't be zero");
+    or die "Framerate can't be zero\n";
 } elsif ($mode eq 'shift') {
-  $opts{shifttime}
-    or usage("You should set '-t' option in this mode");
-  (not $opts{shiftstart} or $opts{shiftstart} > 0.0)
-    or usage("Shift start must be positive time");
-  (not $opts{shiftend}   or $opts{shiftend} > 0.0)
-    or usage("Shift end must be positive time");
-  (not $opts{shiftlen}   or $opts{shiftlen} > 0.0)
-    or usage("Shift length must be positive time");
-} elsif ($mode eq 'points') {
   scalar(@points)
-    or usage("You should specify at least one shift point");
-  foreach my $point (@points) {
-    ...
-  }
+    or die "You should specify at least one timepoint\n";
+  ($opts{amode} eq 'seq' or $opts{amode} eq 'rst')
+    or die "Value of -m option should be 'seq' or 'rst'\n";
+} elsif ($mode eq 'drift') {
+  scalar(@points)
+    or die "You should specify at least one timepoint\n";
 } else {
-  usage("Incorrect mode: $mode (see help below)");
+  usage();
 }
 
+$opts{infile}
+  or die "No input file\n";
+
 my $ssa = Subtitle::Format::SSA->new(debug => !!$opts{loglevel});
 unless ($ssa->from_file($opts{infile})) {
   foreach my $line (@{ $ssa->{log} }) {
@@ -110,25 +107,45 @@ unless ($ssa->from_file($opts{infile})) {
   exit 1;
 }
 
+if (@points) {
+  @points = sort { $a->time <=> $b->time } @points;
+}
+
 if ($mode eq 'framerate') {
   my $mod = $opts{inrate} / $opts{outrate};
-  foreach my $event (@{ $ssa->{events} }) {
-    $event->{start} *= $mod;
-    $event->{end}   *= $mod;
+  foreach my $e (@{ $ssa->events }) {
+    $e->t_start($e->t_start * $mod);
+    $e->t_start($e->t_end   * $mod);
   }
 } elsif ($mode eq 'shift') {
-  my $style = $opts{style};
-  my $start = $opts{shiftstart} // 0.0;
-  my $end   = $opts{shiftend} // (($opts{shiftlen}) ? $start + $opts{shiftend} : undef);
-  my $mod   = $opts{shifttime};
-  foreach my $event (@{ $ssa->{events} }) {
-    next if ($style and $event->{style} ne $style);
-    next if ($start and $event->{start} < $start);
-    next if ($end   and $event->{end}   > $end);
-    $event->{start} += $mod;
-    $event->{end}   += $mod;
+  if ($opts{amode} eq 'seq') {
+    while (my $p = shift @points) {
+      foreach my $e (@{ $ssa->events }) {
+        next if $p->time > $e->t_start;
+        $e->t_start($e->t_start + $p->shift);
+        $e->t_end  ($e->t_end   + $p->shift);
+      } # foreach
+    } # while
+  } elsif ($opts{amode} eq 'rst') {
+    while (my $p = shift @points) {
+      # use time of next point as upper limit for current
+      my $end = @points ? $points[0]->time : 0;
+      foreach my $e (@{ $ssa->events }) {
+        next if $p->time      >  $e->t_start; # too early
+        next if $end and $end <= $e->t_start; # too late
+        $e->t_start($e->t_start + $p->shift);
+        $e->t_end  ($e->t_end   + $p->shift);
+      } # foreach
+    } # while
+  }
+} elsif ($mode eq 'drift') {
+  if ($points[0]->time >= 0.2) {
+    # add starting point
+    my $p = Subtitle::TimePoint->new;
+    $p->parse('0/0');
+    unshift @points, $p;
   }
-} elsif ($mode eq 'points') {
+  # add endpoint
   ...;
 }