diff --git a/sandbox/convert_cftimeset_time_tz.pl b/sandbox/convert_cftimeset_time_tz.pl
new file mode 100644
index 0000000000..408d5e3379
--- /dev/null
+++ b/sandbox/convert_cftimeset_time_tz.pl
@@ -0,0 +1,510 @@
+use strict;
+
+use DateTime qw();
+use DateTime::TimeZone qw();
+
+eval 'use lib "/home/rkrenn/sipwise/git/ngcp-schema/lib";';
+eval 'use lib "/home/rkrenn/sipwise/git/sipwise-base/lib";';
+eval 'use NGCP::Schema;';
+
+my $schema = undef;
+if ($@) {
+    die('failed to load NGCP::Schema: ' . $@);
+} else {
+    print "connecting to ngcp db";
+    $schema = NGCP::Schema->connect({
+        dsn                 => "DBI:mysql:database=provisioning;host=192.168.0.29;port=3306",
+        user                => "root",
+        #password            => "...",
+        mysql_enable_utf8   => "1",
+        on_connect_do       => "SET NAMES utf8mb4",
+        quote_char          => "`",
+    });
+}
+
+goto WRITE_TO_DB;
+
+print "\n" . process_file('/home/rkrenn/temp/cftimeset_tz/cftimesets.txt',sub { #'/home/rkrenn/temp/cftimeset_tz/cftimesets.txt'
+    my $item = shift;
+    my @times;
+    print "\nsubscriber id $item->{subscriber_id} - $item->{timezone}: ";
+    for my $timeelem (@{$item->{voip_cf_periods}}) {
+        delete $timeelem->{'id'};
+        push @times, $timeelem;
+    }
+
+    my $converted_times = apply_owner_timezone(
+        undef,
+        \@times,
+        'inflate',
+        $item->{timezone},
+    );
+
+    if ($converted_times) {
+        #use Data::Dumper;
+        #print Dumper($converted_times);
+        my $indent = 40;
+        for (my $i = 0; $i < ((scalar @{$item->{voip_cf_periods}} > scalar @$converted_times) ? scalar @{$item->{voip_cf_periods}} : scalar @$converted_times); $i++) {
+            my $old = $item->{voip_cf_periods}->[$i];
+            my $new = $converted_times->[$i];
+            my $str = '';
+            $str .= ' ' x $indent unless $old;
+            $str = print_item($old,'time_set_id',$str);
+            $str = print_item($old,'year',$str);
+            $str = print_item($old,'month',$str);
+            $str = print_item($old,'mday',$str);
+            $str = print_item($old,'wday',$str);
+            $str = print_item($old,'hour',$str);
+            $str = print_item($old,'minute',$str);
+            if ($new) {
+                $str .= ' ' x ($indent-length($str));
+                $str = print_item($new,'time_set_id',$str,1);
+                $str = print_item($new,'year',$str);
+                $str = print_item($new,'month',$str);
+                $str = print_item($new,'mday',$str);
+                $str = print_item($new,'wday',$str);
+                $str = print_item($new,'hour',$str);
+                $str = print_item($new,'minute',$str);
+            }
+            print $str . "\n";
+        }
+        return 1;
+    } else {
+        return 0;
+    }
+}) . ' rows processed';
+
+WRITE_TO_DB:
+print "\n" . process_rows('voip_cf_time_sets', sub {
+    my $item = shift;
+    my @times;
+    for my $time ($item->voip_cf_periods->all) {
+        my $timeelem = {$time->get_inflated_columns};
+        delete $timeelem->{'id'};
+        push @times, $timeelem;
+    }
+
+    my $converted_times = apply_owner_timezone(
+        $item->subscriber->voip_subscriber->id,
+        \@times,
+        'inflate',
+    );
+
+    if ($converted_times) {
+        #use Data::Dumper;
+        #print Dumper($converted_times);
+
+        $item->voip_cf_periods->delete;
+        for my $t ( @$converted_times ) {
+            delete $t->{time_set_id};
+            $item->create_related("voip_cf_periods", $t);
+        }
+        return 1;
+    } else {
+        return 0;
+    }
+}) . ' rows processed';
+exit;
+
+sub apply_owner_timezone {
+
+    my ($subscriber_id, $times, $mode, $timezone) = @_;
+
+    my $tz_name;
+    if($timezone) {
+        if (DateTime::TimeZone->is_valid_name($timezone)) {
+            $tz_name = $timezone;
+        } else {
+            warn("timezone '$timezone' is not a valid time zone");
+            return;
+        }
+    } elsif ($subscriber_id) {
+        my $tz = $schema->resultset('voip_subscriber_timezone')->search_rs({
+            subscriber_id => $subscriber_id
+        })->first;
+        $tz_name = normalize_db_tz_name($tz->name) if $tz;
+    }
+    $times //= [];
+    my $tz_local = DateTime::TimeZone->new(name => 'local');
+    my ($tz,$offset);
+    if ($tz_name
+        and ($tz = DateTime::TimeZone->new(name => $tz_name))
+        and abs($offset = $tz->offset_for_datetime(DateTime->now()) - $tz_local->offset_for_datetime(DateTime->now())) > 0) {
+        #print current_local()->hms;
+        my $offset_hrs = int($offset / 3600.0);
+        if ($offset_hrs * 3600 != $offset) {
+            warn("only full hours supported for timezone offset ($tz_name: $offset seconds = $offset_hrs hours)");
+            return;
+        }
+
+        #foreach my $time (@$times) {
+        #    foreach $field (qw(year month mday) {
+        #        if (exists $time->{$field} and $time->{$field}) {
+        #            $self->error($c, HTTP_UNPROCESSABLE_ENTITY, "cannot apply a timezone offset for time with '$field' field ($time->{$field})");
+        #            return;
+        #        }
+        #    }
+        #}
+
+        my $merge = 0;
+        if ('deflate' eq $mode) { #for writing to db
+            $offset_hrs = $offset_hrs * -1;
+            print "cf timeset $mode for timezone $tz_name: offset $offset_hrs hours\n";
+        } elsif ('inflate' eq $mode) { #for reading from db
+            $merge = 1;
+            print "cf timeset $mode for timezone $tz_name: offset $offset_hrs hours\n";
+        } else {
+            die("invalid mode $mode");
+        }
+
+        my ($yearmonthmday_map,$yearmonthmdays) = array_to_map($times,sub { my $time = shift;
+            return (length($time->{year}) > 0 ? $time->{year} : '*') .
+            '_' . ($time->{month} || '*') . '_' . ($time->{mday} || '*');
+        },undef,'group');
+
+        $times = [];
+        foreach my $yearmonthmday (@$yearmonthmdays) {
+            if ($offset_hrs > 0) {
+                push(@$times,@{add($yearmonthmday_map->{$yearmonthmday},$offset_hrs,$merge)});
+            } else {
+                push(@$times,@{subtract($yearmonthmday_map->{$yearmonthmday},$offset_hrs,$merge)});
+            }
+        }
+
+    } else {
+        print "no timezone to convert to, or zero tz offset\n";
+    }
+    return $times;
+
+}
+
+sub process_rows {
+    my ($relation,$code) = @_;
+
+    my $item_rs = $schema->resultset($relation);
+    my $page = 1;
+    my $count = 0;
+    while (my @page = $item_rs->search_rs(undef,{
+        page => $page,
+        rows => 100,
+    })->all) {
+        foreach my $item (@page) {
+            if (&$code($item)) {
+                $count++;
+            }
+        }
+        $page++;
+    }
+    return $count;
+}
+
+sub process_file {
+    my ($filename,$code) = @_;
+    open(my $fh, '<:encoding(UTF-8)', $filename) or die "Could not open file '$filename' $!";
+    my @rows = ();
+    while (my $row = <$fh>) {
+        my @cleaned = map { $_ = s/NULL//gr =~ s/[\r\n]//gir; length($_) > 0 ? $_ : undef; } split(/,/,$row);
+        push(@rows,{
+            id => $cleaned[0],
+            time_set_id => $cleaned[1],
+            year => $cleaned[2],
+            month => $cleaned[3],
+            mday => $cleaned[4],
+            wday => $cleaned[5],
+            hour => $cleaned[6],
+            minute => $cleaned[7],
+            subscriber_id => $cleaned[8],
+            timezone => $cleaned[9],
+        });
+    }
+    close $fh;
+    my ($map,$ids) = array_to_map(\@rows,sub {
+        return shift->{time_set_id};
+    },undef,'group');
+    my $count = 0;
+    foreach my $time_set_id (sort @$ids) {
+        my $item = { voip_cf_periods => [] };
+        foreach my $row (@{$map->{$time_set_id}}) {
+            my $period = { %$row };
+            $item->{subscriber_id} = delete $period->{subscriber_id};
+            $item->{timezone} = delete $period->{timezone};
+            push(@{$item->{voip_cf_periods}},$period);
+        }
+        if (&$code($item)) {
+            $count++;
+        }
+    }
+    return $count;
+}
+
+sub add {
+    my ($times,$offset_hrs,$merge) = @_;
+
+    my @result = ();
+    foreach my $time (@$times) {
+        my $p1 = { %$time };
+        unless (length($time->{hour}) > 0) {
+            #nothing to do if there is no hour defined:
+            push(@result,$p1);
+            next;
+        }
+        my ($hour_start,$hour_end) = split(/\-/, $time->{hour});
+        my $hour_range;
+        if (defined $hour_end) {
+            $hour_range = 1;
+        } else {
+            $hour_end = $hour_start;
+            $hour_range = 0;
+        }
+        $hour_start += abs($offset_hrs);
+        $hour_end += abs($offset_hrs);
+        if ($hour_start < 24 and $hour_end < 24) {
+            $p1->{hour} = ($hour_range ? $hour_start . '-' . $hour_end : $hour_start);
+            push(@result,$p1);
+            next;
+        }
+        my ($wday_start, $wday_end) = split(/\-/, $time->{wday} || '1-7');
+        my $wday_range;
+        if (defined $wday_end) {
+            $wday_range = 1;
+        } else {
+            $wday_end = $wday_start;
+            $wday_range = 0;
+        }
+        my @nums = ();
+        if ($wday_start <= $wday_end) {
+            push(@nums,$wday_start .. $wday_end);
+        } else {
+            push(@nums,$wday_start .. 7);
+            push(@nums,1 .. $wday_end);
+        }
+        my ($p2,$p_shift_wday);
+        if ($hour_start > 23 and $hour_end > 23) { #26-28
+            $p1->{hour} = ($hour_range ? ($hour_start % 24) . '-' . ($hour_end % 24) : ($hour_start % 24)); #2-4
+            $p_shift_wday = $p1;
+        } elsif ($hour_start < $hour_end) {
+            if ($hour_end > 23) { #17-23 +3-> 20-26
+                $p1->{hour} = $hour_start . '-23'; #20-0
+                $p2 = { %$time };
+                $p2->{hour} = '0-' . ($hour_end % 24); #0-2
+                $p_shift_wday = $p2;
+            }
+        } else {
+            if ($hour_start > 23) { #23-17 +3-> 26-20
+                $p1->{hour} = ($hour_start % 24) . '-' . $hour_end; #2-20
+                $p_shift_wday = $p1;
+            }
+        }
+        if ($p_shift_wday and (scalar @nums) < 7) {
+            $p_shift_wday->{wday} = ($wday_range ? (($wday_start) % 7 + 1) . '-' . (($wday_end) % 7 + 1) : (($wday_start) % 7 + 1));
+        }
+        push(@result,$p1);
+        push(@result,$p2) if $p2;
+    }
+    return ($merge ? merge_adjacent(\@result) : \@result);
+
+}
+
+sub subtract {
+    my ($times,$offset_hrs,$merge) = @_;
+
+    my @result = ();
+    foreach my $time (@$times) {
+        my $p1 = { %$time };
+        unless (length($time->{hour}) > 0) {
+            #nothing to do if there is no hour defined:
+            push(@result,$p1);
+            next;
+        }
+        my ($hour_start,$hour_end) = split(/\-/, $time->{hour});
+        my $hour_range;
+        if (defined $hour_end) {
+            $hour_range = 1;
+        } else {
+            $hour_end = $hour_start;
+            $hour_range = 0;
+        }
+        $hour_start -= abs($offset_hrs);
+        $hour_end -= abs($offset_hrs);
+        if ($hour_start >= 0 and $hour_end >= 0) {
+            $p1->{hour} = ($hour_range ? $hour_start . '-' . $hour_end : $hour_start);
+            push(@result,$p1);
+            next;
+        }
+        my ($wday_start, $wday_end) = split(/\-/, $time->{wday} || '1-7');
+        my $wday_range;
+        if (defined $wday_end) {
+            $wday_range = 1;
+        } else {
+            $wday_end = $wday_start;
+            $wday_range = 0;
+        }
+        my @nums = ();
+        if ($wday_start <= $wday_end) {
+            push(@nums,$wday_start .. $wday_end);
+        } else {
+            push(@nums,$wday_start .. 7);
+            push(@nums,1 .. $wday_end);
+        }
+        my ($p2,$p_shift_wday);
+        if ($hour_start < 0 and $hour_end < 0) { #-4 - -2
+            $p1->{hour} = ($hour_range ? ($hour_start % 24) . '-' . ($hour_end % 24) : ($hour_start % 24)); #20-22
+            $p_shift_wday = $p1;
+        } elsif ($hour_start < $hour_end) { #-4 - 3
+            if ($hour_start < 0) { #0-7 -4-> -4 - 3
+                $p1->{hour} = ($hour_start % 24) . '-23'; #20-0
+                $p2 = { %$time };
+                $p2->{hour} = '0-' . $hour_end; #0-3
+                $p_shift_wday = $p1;
+            }
+        } else {
+            if ($hour_end < 0) { #22 - 2 -6-> 16 - -4
+                $p1->{hour} = $hour_start . '-' . ($hour_end % 24); #16-20
+                $p_shift_wday = $p1;
+            }
+        }
+        if ($p_shift_wday and (scalar @nums) < 7) {
+            $p_shift_wday->{wday} = ($wday_range ? (($wday_start - 2) % 7 + 1) . '-' . (($wday_end - 2) % 7 + 1) : (($wday_start - 2) % 7 + 1));
+        }
+        push(@result,$p1);
+        push(@result,$p2) if $p2;
+    }
+    return ($merge ? merge_adjacent(\@result) : \@result);
+
+}
+
+sub merge_adjacent {
+    my ($times) = @_;
+
+    my ($wday_map,$wdays) = array_to_map($times,sub { my $time = shift;
+        my $wday = $time->{wday} || '1-7';
+        $wday = '1-7' if $time->{wday} eq '7-1';
+        $wday .= '_' . (defined $time->{minute} ? $time->{minute} : '*');
+        return $wday;
+    },undef,'group');
+
+    my @result = ();
+    my $idx = 0;
+    foreach my $wday (@$wdays) {
+        my %hour_start_map = ();
+        my %hour_end_map = ();
+        my %skip_map = ();
+        my $old_idx = $idx;
+        foreach my $time (@{$wday_map->{$wday}}) {
+            if (length($time->{hour}) > 0) {
+                my ($hour_start,$hour_end) = split(/\-/, $time->{hour});
+                $hour_end //= $hour_start;
+                if ($hour_end >= $hour_start) { #we do not create any adjacent roll-over hours, so we also skip such when merging
+                    if (not defined $hour_start_map{$hour_start}
+                        or $hour_end > $hour_start_map{$hour_start}->{hour_end}) {
+                        $hour_start_map{$hour_start} = { hour_end => $hour_end, idx => $idx, };
+                    } else {
+                        $skip_map{$idx} = 0;
+                    }
+                    if (not defined $hour_end_map{$hour_end}
+                        or $hour_start < $hour_end_map{$hour_end}->{hour_start}) {
+                        $hour_end_map{$hour_end} = { hour_start => $hour_start, }; #, idx => $idx,
+                    } else {
+                        $skip_map{$idx} = 0;
+                    }
+                } else {
+                    $skip_map{$idx} = 1;
+                }
+            } else {
+                $skip_map{$idx} = 1;
+            }
+            $idx++;
+        }
+        $idx = $old_idx;
+        foreach my $time (@{$wday_map->{$wday}}) {
+            my $p = { %$time };
+            if (exists $skip_map{$idx}) {
+                push(@result,$p) if $skip_map{$idx};
+            } else {
+                my ($hour_start,$hour_end) = split(/\-/, $time->{hour});
+                $hour_end //= $hour_start;
+                #if ($hour_end_map{$hour_end}->{idx} == $idx) {
+                    my $adjacent_start = $hour_end + 1;
+                    if (exists $hour_start_map{$adjacent_start}) {
+                        $p->{hour} = $hour_start . '-' . $hour_start_map{$adjacent_start}->{hour_end};
+                        $skip_map{$hour_start_map{$adjacent_start}->{idx}} = 0;
+                    }
+                    push(@result,$p);
+                #}
+            }
+            $idx++;
+        }
+    }
+    return \@result;
+}
+
+sub array_to_map {
+
+    my ($array_ptr,$get_key_code,$get_value_code,$mode) = @_;
+    my $map = {};
+    my @keys = ();
+    my @values = ();
+    if (defined $array_ptr and ref $array_ptr eq 'ARRAY') {
+        if (defined $get_key_code and ref $get_key_code eq 'CODE') {
+            if (not (defined $get_value_code and ref $get_value_code eq 'CODE')) {
+                $get_value_code = sub { return shift; };
+            }
+            $mode = lc($mode);
+            if (not ($mode eq 'group' or $mode eq 'first' or $mode eq 'last')) {
+                $mode = 'group';
+            }
+            foreach my $item (@$array_ptr) {
+                my $key = &$get_key_code($item);
+                if (defined $key) {
+                    my $value = &$get_value_code($item);
+                    if (defined $value) {
+                        if (not exists $map->{$key}) {
+                            if ($mode eq 'group') {
+                                $map->{$key} = [ $value ];
+                            } else {
+                                $map->{$key} = $value;
+                            }
+                            push(@keys,$key);
+                        } else {
+                            if ($mode eq 'group') {
+                                push(@{$map->{$key}}, $value);
+                            } elsif ($mode eq 'last') {
+                                $map->{$key} = $value;
+                            }
+                        }
+                        push(@values,$value);
+                    }
+                }
+            }
+        }
+    }
+    return ($map,\@keys,\@values);
+
+}
+
+sub normalize_db_tz_name {
+    my $tz = shift;
+    if (defined $tz) {
+        if (lc($tz) eq 'localtime') {
+            $tz = 'local';
+        } elsif (lc($tz) eq 'system') {
+            $tz = 'local';
+        } # else { ... additional cases
+    }
+    return $tz;
+}
+
+sub current_local {
+    return DateTime->now(
+        time_zone => DateTime::TimeZone->new(name => 'local'),
+    );
+}
+
+sub print_item {
+    my ($item,$field,$str,$no_sep) = @_;
+    if ($item) {
+        $str .= ',' if (length($str) > 0 and not $no_sep);
+        $str .= ($item->{$field} // 'NULL');
+    }
+    return $str;
+}