diff --git a/config.py b/config.py
index 226272c..66d5e41 100644
--- a/config.py
+++ b/config.py
@@ -4,14 +4,17 @@
 # full copyright notices and license terms.
 
 
+from datetime import date, timedelta
+from dateutil.easter import (
+    easter, EASTER_JULIAN, EASTER_ORTHODOX, EASTER_WESTERN)
 from trytond.pool import PoolMeta, Pool
 from trytond.model import fields
 
 holidays = fields.Char(
-    string='Holidays', help='Semicolon separate list of dates:' +
-    ' yyyy-mm-dd = single date, mm-dd = annual repetition, ' +
-    'easter = Easter Sunday, ascension = Ascension Day, offset ' +
-    'with +/-n e.g.: easter+1 = Easter Monday')
+    string='Holidays', help='Semicolon separate list of dates: ' +
+    'yyyy-mm-dd = single date, mm-dd = annual repetition, ' +
+    'easter[greg|jul|orth] = Easter Sunday, ascension = Ascension Day, ' +
+    'whitsun = Whitsunday, offset with :+/-n e.g.: easter:+1 = Easter Monday')
 
 
 class Configuration(metaclass=PoolMeta):
@@ -19,6 +22,137 @@ class Configuration(metaclass=PoolMeta):
 
     holidays = fields.MultiValue(holidays)
 
+    def holiday_dates(self, years=[]):
+        """ get list of dates for list of years
+
+        Args:
+            years (list, optional): years to get holidays for. Defaults to [].
+
+        Returns:
+            list of date: holidays for requestd years
+        """
+        pool = Pool()
+        IrDate = pool.get('ir.date')
+        Config = pool.get('cashbook.configuration')
+
+        if not years:
+            years = [IrDate.today().year]
+
+        cfg1 = Config.get_singleton()
+        if not (cfg1 and cfg1.holidays and isinstance(cfg1.holidays, str)):
+            return []
+        return Config.holiday_parseconfig(cfg1.holidays, years)['dates']
+
+    @classmethod
+    def holiday_parseconfig(cls, holiday_string, years=[]):
+        """ read holiday config, generate parsed list of defines
+
+        Args:
+            holiday_string (str): holiday definition string
+            years (list of int): years to generate dates for
+
+        Returns:
+            dict: {'definition': '<parsed definition string>',
+                'dates': [<requested dates>]}
+        """
+        IrDate = Pool().get('ir.date')
+
+        def parse_date_offet(offset_str):
+            """ parse offset string
+
+            Args:
+                offset_str (str): '+n' or '-n'
+
+            Returns:
+                tuple: (int(offset), 'offset-string')
+            """
+            # decode ':+n' or ':-n'
+            offset_value = 0
+            plus_sign = 1
+            if offset_str:
+                plus_sign = -1 if offset_str.startswith('-') else 1
+                date_offset = offset_str[1:]
+                if date_offset.isdigit():
+                    offset_value = int(date_offset)
+            return (offset_value * plus_sign, '%(sign)s%(amount)d' % {
+                'sign': '+' if plus_sign >= 0 else '-',
+                'amount': offset_value})
+
+        def parse_date_definition(date_str, years):
+            """ parse date definition string, generate list of
+            dates
+
+            Args:
+                date_str (str): definition string
+                years (list of int): years to generate dates for
+
+            Returns:
+                _type_: _description_
+            """
+            dates = []
+            date_def = ''
+            easter_type = {
+                'greg': EASTER_WESTERN, 'jul': EASTER_JULIAN,
+                'orth': EASTER_ORTHODOX}
+
+            date_str = date_str.lower()
+            # first parse easter-based dates
+            for dt_calc in [
+                    {'type': 'easter', 'days': 0},
+                    {'type': 'ascension', 'days': 39},
+                    {'type': 'whitsun', 'days': 49}]:
+                if date_str.startswith(dt_calc['type']):
+                    e_meth = date_str[len(dt_calc['type']):]
+                    easter_meth = easter_type.get(e_meth, EASTER_WESTERN)
+                    dates.extend([
+                        easter(x, easter_meth) +
+                        timedelta(days=dt_calc['days'])
+                        for x in years])
+                    date_def = date_str
+
+            # if not detected try date string
+            if not date_def:
+                date_fields = date_str.split('-')
+                try:
+                    if len(date_fields) == 3:
+                        dates.append(date.fromisoformat(date_str))
+                        date_def = date_str
+                    elif len(date_fields) == 2:
+                        for year in years:
+                            dates.append(date.fromisoformat(
+                                str(year) + '-' + date_str))
+                        date_def = date_str
+                except Exception:
+                    pass
+            return (dates, date_def)
+
+        if not (holiday_string and isinstance(holiday_string, str)):
+            return {'definition': '', 'dates': []}
+
+        if not years:
+            years = [IrDate.today().year]
+
+        parsed_str = []
+        parsed_dates = []
+        for datedef in holiday_string.split(';'):
+            if not datedef:
+                continue
+
+            datedef = datedef.strip().split(':')
+            date_offset = datedef[1] if len(datedef) > 1 else ''
+
+            (date_offset, offset_str) = parse_date_offet(date_offset)
+            (date_lst, date_def) = parse_date_definition(datedef[0], years)
+
+            parsed_dates.extend([
+                x + timedelta(days=date_offset)
+                for x in date_lst])
+            if date_def:
+                if date_offset != 0:
+                    date_def += ':' + offset_str
+                parsed_str.append(date_def)
+        return {'definition': ';'.join(parsed_str), 'dates': parsed_dates}
+
     @classmethod
     def multivalue_model(cls, field):
         """ get model for value
diff --git a/locale/de.po b/locale/de.po
index 140a7d2..5d4d025 100644
--- a/locale/de.po
+++ b/locale/de.po
@@ -91,8 +91,8 @@ msgid "Holidays"
 msgstr "Feiertage"
 
 msgctxt "help:cashbook.configuration,holidays:"
-msgid "Semicolon separate list of dates: yyyy-mm-dd = single date, mm-dd = annual repetition, easter = Easter Sunday, ascension = Ascension Day, offset with +/-n e.g.: easter+1 = Easter Monday"
-msgstr "Semikolon getrennte Liste von Datumswerten: yyyy-mm-dd = Einzeldatum, mm-dd = jährliche Wiederholung, easter = Ostersonntag, ascension = Christi Himmelfahrt, Offset mit +/-n z.B: easter+1 = Ostermontag"
+msgid "Semicolon separate list of dates: yyyy-mm-dd = single date, mm-dd = annual repetition, easter[greg|jul|orth] = Easter Sunday, ascension = Ascension Day, whitsun = Whitsunday, offset with :+/-n e.g.: easter:+1 = Easter Monday"
+msgstr "Semikolon getrennte Liste von Datumswerten: yyyy-mm-dd = Einzeldatum, mm-dd = jährliche Wiederholung, easter[greg|jul|orth] = Ostersonntag, ascension = Christi Himmelfahrt, whitsun = Pfingstsonntag, Offset mit :+/-n z.B: easter:+1 = Ostermontag"
 
 
 ####################
diff --git a/locale/en.po b/locale/en.po
index abdc601..814fbea 100644
--- a/locale/en.po
+++ b/locale/en.po
@@ -67,8 +67,8 @@ msgid "Holidays"
 msgstr "Holidays"
 
 msgctxt "help:cashbook.configuration,holidays:"
-msgid "Semicolon separate list of dates: yyyy-mm-dd = single date, mm-dd = annual repetition, easter = Easter Sunday, ascension = Ascension Day, offset with +/-n e.g.: easter+1 = Easter Monday"
-msgstr "Semicolon separate list of dates: yyyy-mm-dd = single date, mm-dd = annual repetition, easter = Easter Sunday, ascension = Ascension Day, offset with +/-n e.g.: easter+1 = Easter Monday"
+msgid "Semicolon separate list of dates: yyyy-mm-dd = single date, mm-dd = annual repetition, easter[greg|jul|orth] = Easter Sunday, ascension = Ascension Day, whitsun = Whitsunday, offset with :+/-n e.g.: easter:+1 = Easter Monday"
+msgstr "Semicolon separate list of dates: yyyy-mm-dd = single date, mm-dd = annual repetition, easter[greg|jul|orth] = Easter Sunday, ascension = Ascension Day, whitsun = Whitsunday, offset with :+/-n e.g.: easter:+1 = Easter Monday"
 
 msgctxt "model:cashbook.planner,name:"
 msgid "Scheduled Booking"
diff --git a/tests/planner.py b/tests/planner.py
index d9ad9e7..a250efd 100644
--- a/tests/planner.py
+++ b/tests/planner.py
@@ -116,6 +116,52 @@ class PlannerTestCase(object):
                 'Depot | 0.00 usd | Open | 0.0000 u')
         return book
 
+    @with_transaction()
+    def test_func_holiday_parseconfig(self):
+        """ check function holiday_parseconfig()
+        """
+        Config = Pool().get('cashbook.configuration')
+
+        company = self.prep_company()
+        with Transaction().set_context({'company': company.id}):
+            # check valid data
+            result = Config.holiday_parseconfig(
+                '2022-05-01;12-25;12-25:+1;easter;easter:-2;easterjul;' +
+                'ascension;whitsun;whitsun:+1;',
+                [2022, 2023, 2024])
+            self.assertEqual(result, {
+                'definition': '2022-05-01;12-25;12-25:+1;easter;easter:-2;' +
+                'easterjul;ascension;whitsun;whitsun:+1',
+                'dates': [
+                    date(2022, 5, 1), date(2022, 12, 25), date(2023, 12, 25),
+                    date(2024, 12, 25), date(2022, 12, 26), date(2023, 12, 26),
+                    date(2024, 12, 26), date(2022, 4, 17), date(2023, 4, 9),
+                    date(2024, 3, 31), date(2022, 4, 15), date(2023, 4, 7),
+                    date(2024, 3, 29), date(2022, 4, 11), date(2023, 4, 3),
+                    date(2024, 4, 22), date(2022, 5, 26), date(2023, 5, 18),
+                    date(2024, 5, 9), date(2022, 6, 5), date(2023, 5, 28),
+                    date(2024, 5, 19), date(2022, 6, 6), date(2023, 5, 29),
+                    date(2024, 5, 20)]})
+
+            # check invalid data
+            self.assertEqual(
+                Config.holiday_parseconfig('not-a-value;'),
+                {'definition': '', 'dates': []})
+
+            # check no data
+            self.assertEqual(
+                Config.holiday_parseconfig(''),
+                {'definition': '', 'dates': []})
+            self.assertEqual(
+                Config.holiday_parseconfig(None),
+                {'definition': '', 'dates': []})
+
+            cfg1 = Config(holidays='2022-05-01;easter;whitsun')
+            cfg1.save()
+            self.assertEqual(
+                cfg1.holiday_dates([2022]),
+                [date(2022, 5, 1), date(2022, 4, 17), date(2022, 6, 5)])
+
     @with_transaction()
     def test_planner_create_job(self):
         """ create job, check rule + constraints