diff --git a/src/PVE/CalendarEvent.pm b/src/PVE/CalendarEvent.pm
index 56e9923..e2bf53a 100644
--- a/src/PVE/CalendarEvent.pm
+++ b/src/PVE/CalendarEvent.pm
@@ -6,6 +6,7 @@ use Data::Dumper;
 use Time::Local;
 use PVE::JSONSchema;
 use PVE::Tools qw(trim);
+use PVE::RS::CalendarEvent;
 
 # Note: This class implements a parser/utils for systemd like calendar exents
 # Date specification is currently not implemented
@@ -43,259 +44,13 @@ sub parse_calendar_event {
 	die "unable to parse calendar event - event is empty\n";
     }
 
-    my $parse_single_timespec = sub {
-	my ($p, $max, $matchall_ref, $res_hash) = @_;
-
-	if ($p =~ m/^((?:\*|[0-9]+))(?:\/([1-9][0-9]*))?$/) {
-	    my ($start, $repetition) = ($1, $2);
-	    if (defined($repetition)) {
-		$repetition = int($repetition);
-		$start = $start eq '*' ? 0 : int($start);
-		die "value '$start' out of range\n" if $start >= $max;
-		die "repetition '$repetition' out of range\n" if $repetition >= $max;
-		while ($start < $max) {
-		    $res_hash->{$start} = 1;
-		    $start += $repetition;
-		}
-	    } else {
-		if ($start eq '*') {
-		    $$matchall_ref = 1;
-		} else {
-		    $start = int($start);
-		    die "value '$start' out of range\n" if $start >= $max;
-		    $res_hash->{$start} = 1;
-		}
-	    }
-	} elsif ($p =~ m/^([0-9]+)\.\.([1-9][0-9]*)$/) {
-	    my ($start, $end) = (int($1), int($2));
-	    die "range start '$start' out of range\n" if $start >= $max;
-	    die "range end '$end' out of range\n" if $end >= $max || $end < $start;
-	    for (my $i = $start; $i <= $end; $i++) {
-		$res_hash->{$i} = 1;
-	    }
-	} else {
-	    die "unable to parse calendar event '$p'\n";
-	}
-    };
-
-    my $h = undef;
-    my $m = undef;
-
-    my $matchall_minutes = 0;
-    my $matchall_hours = 0;
-    my $minutes_hash = {};
-    my $hours_hash = {};
-
-    my $dowsel = join('|', keys %$dow_names);
-
-    my $dow_hash;
-
-    my $parse_dowspec = sub {
-	my ($p) = @_;
-
-	if ($p =~ m/^($dowsel)$/i) {
-	    $dow_hash->{$dow_names->{lc($1)}} = 1;
-	} elsif ($p =~ m/^($dowsel)\.\.($dowsel)$/i) {
-	    my $start = $dow_names->{lc($1)};
-	    my $end = $dow_names->{lc($2)} || 7;
-	    die "wrong order in range '$p'\n" if $end < $start;
-	    for (my $i = $start; $i <= $end; $i++) {
-		$dow_hash->{($i % 7)} = 1;
-	    }
-	} else {
-	    die "unable to parse weekday specification '$p'\n";
-	}
-    };
-
-    my @parts = split(/\s+/, $event);
-    my $utc = (@parts && uc($parts[-1]) eq 'UTC');
-    pop @parts if $utc;
-
-
-    if ($parts[0] =~ m/$dowsel/i) {
-	my $dow_spec = shift @parts;
-	foreach my $p (split(',', $dow_spec)) {
-	    $parse_dowspec->($p);
-	}
-    } else {
-	$dow_hash = { 0 => 1, 1 => 1, 2 => 1, 3 => 1, 4 => 1, 5=> 1, 6 => 1 };
-    }
-
-    if (scalar(@parts) && $parts[0] =~ m/\-/) {
-	my $date_spec = shift @parts;
-	die "date specification not implemented";
-    }
-
-    my $time_spec = shift(@parts) // "00:00";
-    my $chars = '[0-9*/.,]';
-
-    if ($time_spec =~ m/^($chars+):($chars+)$/) {
-	my ($p1, $p2) = ($1, $2);
-	foreach my $p (split(',', $p1)) {
-	    $parse_single_timespec->($p, 24, \$matchall_hours, $hours_hash);
-	}
-	foreach my $p (split(',', $p2)) {
-	    $parse_single_timespec->($p, 60, \$matchall_minutes, $minutes_hash);
-	}
-    } elsif ($time_spec =~ m/^($chars)+$/) { # minutes only
-	$matchall_hours = 1;
-	foreach my $p (split(',', $time_spec)) {
-	    $parse_single_timespec->($p, 60, \$matchall_minutes, $minutes_hash);
-	}
-
-    } else {
-	die "unable to parse calendar event\n";
-    }
-
-    die "unable to parse calendar event - unused parts\n" if scalar(@parts);
-
-    if ($matchall_hours) {
-	$h = '*';
-    } else {
-	$h = [ sort { $a <=> $b } keys %$hours_hash ];
-    }
-
-    if ($matchall_minutes) {
-	$m = '*';
-    } else {
-	$m = [ sort { $a <=> $b } keys %$minutes_hash ];
-    }
-
-    return { h => $h, m => $m, dow => [ sort keys %$dow_hash ], utc => $utc };
-}
-
-sub is_leap_year($) {
-    return 0 if $_[0] % 4;
-    return 1 if $_[0] % 100;
-    return 0 if $_[0] % 400;
-    return 1;
-}
-
-# mon = 0.. (Jan = 0)
-sub days_in_month($$) {
-    my ($mon, $year) = @_;
-    return 28 + is_leap_year($year) if $mon == 1;
-    return (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)[$mon];
-}
-
-# day = 1..
-# mon = 0.. (Jan = 0)
-sub wrap_time($) {
-    my ($time) = @_;
-    my ($sec, $min, $hour, $day, $mon, $year, $wday) = @$time;
-
-    use integer;
-    if ($sec >= 60) {
-	$min += $sec / 60;
-	$sec %= 60;
-    }
-
-    if ($min >= 60) {
-	$hour += $min / 60;
-	$min %= 60;
-    }
-
-    if ($hour >= 24) {
-	$day  += $hour / 24;
-	$wday += $hour / 24;
-	$hour %= 24;
-    }
-
-    # Translate to 0..($days_in_mon-1)
-    --$day;
-    while (1) {
-	my $days_in_mon = days_in_month($mon % 12, $year);
-	last if $day < $days_in_mon;
-	# Wrap one month
-	$day -= $days_in_mon;
-	++$mon;
-    }
-    # Translate back to 1..$days_in_mon
-    ++$day;
-
-    if ($mon >= 12) {
-	$year += $mon / 12;
-	$mon %= 12;
-    }
-
-    $wday %= 7;
-    return [$sec, $min, $hour, $day, $mon, $year, $wday];
-}
-
-# helper as we need to keep weekdays in sync
-sub time_add_days($$) {
-    my ($time, $inc) = @_;
-    my ($sec, $min, $hour, $day, $mon, $year, $wday) = @$time;
-    return wrap_time([$sec, $min, $hour, $day + $inc, $mon, $year, $wday + $inc]);
+    return PVE::RS::CalendarEvent->new($event);
 }
 
 sub compute_next_event {
     my ($calspec, $last) = @_;
 
-    my $hspec = $calspec->{h};
-    my $mspec = $calspec->{m};
-    my $dowspec = $calspec->{dow};
-    my $utc = $calspec->{utc};
-
-    $last += 60; # at least one minute later
-
-    my $t = [$utc ? gmtime($last) : localtime($last)];
-    $t->[0] = 0;     # we're not interested in seconds, actually
-    $t->[5] += 1900; # real years for clarity
-
-    outer: for (my $i = 0; $i < 1000; ++$i) {
-	my $wday = $t->[6];
-	foreach my $d (@$dowspec) {
-	    goto this_wday if $d == $wday;
-	    if ($d > $wday) {
-		$t->[0] = $t->[1] = $t->[2] = 0; # sec = min = hour = 0
-		$t = time_add_days($t, $d - $wday);
-		next outer;
-	    }
-	}
-	# Test next week:
-	$t->[0] = $t->[1] = $t->[2] = 0; # sec = min = hour = 0
-	$t = time_add_days($t, 7 - $wday);
-	next outer;
-    this_wday:
-
-	goto this_hour if $hspec eq '*';
-	my $hour = $t->[2];
-	foreach my $h (@$hspec) {
-	    goto this_hour if $h == $hour;
-	    if ($h > $hour) {
-		$t->[0] = $t->[1] = 0; # sec = min = 0
-		$t->[2] = $h;          # hour = $h
-		next outer;
-	    }
-	}
-	# Test next day:
-	$t->[0] = $t->[1] = $t->[2] = 0; # sec = min = hour = 0
-	$t = time_add_days($t, 1);
-	next outer;
-    this_hour:
-
-	goto this_min if $mspec eq '*';
-	my $min = $t->[1];
-	foreach my $m (@$mspec) {
-	    goto this_min if $m == $min;
-	    if ($m > $min) {
-		$t->[0] = 0;  # sec = 0
-		$t->[1] = $m; # min = $m
-		next outer;
-	    }
-	}
-	# Test next hour:
-	$t->[0] = $t->[1] = 0; # sec = min = hour = 0
-	$t->[2]++;
-	$t = wrap_time($t);
-	next outer;
-    this_min:
-
-	return $utc ? timegm(@$t) : timelocal(@$t);
-    }
-
-    die "unable to compute next calendar event\n";
+    return $calspec->compute_next_event($last);
 }
 
 1;
diff --git a/test/calendar_event_test.pl b/test/calendar_event_test.pl
index abbd74c..4572965 100755
--- a/test/calendar_event_test.pl
+++ b/test/calendar_event_test.pl
@@ -18,7 +18,7 @@ my $alldays = [0,1,2,3,4,5,6];
 my $tests = [
     [
      '*',
-     { h => '*', m => '*', dow => $alldays },
+     undef,
      [
       [0, 60],
       [30, 60],
@@ -28,7 +28,7 @@ my $tests = [
     ],
     [
      '*/10',
-     { h => '*', m => [0, 10, 20, 30, 40, 50], dow => $alldays },
+     undef,
      [
       [0, 600],
       [599, 600],
@@ -38,7 +38,7 @@ my $tests = [
     ],
     [
      '*/12:0' ,
-     { h => [0, 12], m => [0], dow => $alldays },
+     undef,
      [
       [ 10, 43200],
       [ 13*3600, 24*3600],
@@ -46,7 +46,7 @@ my $tests = [
     ],
     [
      '1/12:0/15' ,
-     { h => [1, 13], m => [0, 15, 30, 45], dow => $alldays },
+     undef,
      [
       [0, 3600],
       [3600, 3600+15*60],
@@ -61,7 +61,7 @@ my $tests = [
     ],
     [
      '1,4,6',
-     { h => '*', m => [1, 4, 6], dow => $alldays},
+     undef,
      [
       [0, 60],
       [60, 4*60],
@@ -71,15 +71,15 @@ my $tests = [
     ],
     [
      '0..3',
-     { h => '*', m => [ 0, 1, 2, 3 ], dow => $alldays },
+     undef,
     ],
     [
      '23..23:0..3',
-     { h => [ 23 ], m => [ 0, 1, 2, 3 ], dow => $alldays },
+     undef,
     ],
     [
      'Mon',
-     { h => [0], m => [0], dow => [1] },
+     undef,
      [
       [0, 4*86400], # Note: Epoch 0 is Thursday, 1. January 1970
       [4*86400, 11*86400],
@@ -88,7 +88,7 @@ my $tests = [
     ],
     [
      'sat..sun',
-     { h => [0], m => [0], dow => [0, 6] },
+     undef,
      [
       [0, 2*86400],
       [2*86400, 3*86400],
@@ -97,7 +97,7 @@ my $tests = [
     ],
     [
      'sun..sat',
-     { h => [0], m => [0], dow => $alldays },
+     undef,
     ],
     [
      'Fri..Mon',
@@ -105,15 +105,15 @@ my $tests = [
     ],
     [
      'wed,mon..tue,fri',
-     { h => [0], m => [0], dow => [ 1, 2, 3, 5] },
+     undef,
     ],
     [
      'mon */15',
-     { h => '*', m =>  [0, 15, 30, 45], dow => [1]},
+     undef,
     ],
     [
     '22/1:0',
-     { h => [22, 23], m => [0], dow => $alldays },
+    undef,
      [
 	[0, 22*60*60],
 	[22*60*60, 23*60*60],
@@ -122,7 +122,7 @@ my $tests = [
     ],
     [
      '*/2:*',
-     { h => [0,2,4,6,8,10,12,14,16,18,20,22], m => '*', dow => $alldays },
+     undef,
      [
 	[0, 60],
 	[60*60, 2*60*60],
@@ -131,7 +131,7 @@ my $tests = [
     ],
     [
      '20..22:*/30',
-     { h => [20,21,22], m => [0,30], dow => $alldays },
+     undef,
      [
 	[0, 20*60*60],
 	[20*60*60, 20*60*60 + 30*60],
@@ -164,7 +164,7 @@ my $tests = [
     ],
     [
      '0,1,3..5',
-     { h => '*', m => [0,1,3,4,5], dow => $alldays },
+     undef,
      [
 	[0, 60],
 	[60, 3*60],
@@ -173,7 +173,7 @@ my $tests = [
     ],
     [
      '2,4:0,1,3..5',
-     { h => [2,4], m => [0,1,3,4,5], dow => $alldays },
+     undef,
      [
 	[0, 2*60*60],
 	[2*60*60 + 60, 2*60*60 + 3*60],
@@ -185,18 +185,16 @@ my $tests = [
 foreach my $test (@$tests) {
     my ($t, $expect, $nextsync) = @$test;
 
+    $expect //= {};
+
     my $timespec;
     eval { $timespec = PVE::CalendarEvent::parse_calendar_event($t); };
     my $err = $@;
-    delete $timespec->{utc};
 
     if ($expect->{error}) {
 	chomp $err if $err;
-	$timespec = { error => $err } if $err;
-	is_deeply($timespec, $expect, "expect parse error on '$t' - $expect->{error}");
+	ok(defined($err) == defined($expect->{error}), "parsing '$t' failed expectedly");
 	die "unable to execute nextsync tests" if $nextsync;
-    } else {
-	is_deeply($timespec, $expect, "parse '$t'");
     }
 
     next if !$nextsync;