diff --git a/birthdays-cal.py b/birthdays-cal.py
new file mode 100644
index 0000000..f7deb65
--- /dev/null
+++ b/birthdays-cal.py
@@ -0,0 +1,114 @@
+
+# -*- coding: utf-8 -*-
+
+import sys
+import yaml
+import datetime
+import hashlib
+from icalendar import Calendar, Event
+
+one_day = datetime.date(1, 1, 2) - datetime.date(1, 1, 1)
+
+event_config = {'description': '', 'categories': '', 'language': ''}
+
+
+def load_config():
+    result = dict()
+    with open('config.yml', 'r', encoding='utf-8') as f:
+        result = yaml.load(f)
+    return result
+
+
+def write_calendar(cal, filename):
+    with open(filename, 'wb') as f:
+        f.write(cal.to_ical())
+
+
+def parse_dates(birthdays):
+    for item in birthdays:
+        person = item['person']
+        birthday_str = person['birthday']
+        if len(birthday_str) == 5:
+            person['birthday_no_year'] = True
+            birthday_str = birthday_str.replace(birthday_str[2], '.')
+            birthday_str = birthday_str + '.0001'
+        person['birthday'] = datetime.datetime.strptime(
+            birthday_str, '%d.%m.%Y').date()
+
+
+def display(cal):
+    print(cal.to_ical().decode('utf-8'))
+
+
+def sha1(string):
+    if isinstance(string, str):
+        string = string.encode('utf8')
+    h = hashlib.sha1()
+    h.update(string)
+    return h.hexdigest()
+
+
+def age(person, year):
+    return abs(year - person['birthday'].year)
+
+
+def make_event(person, year):
+    event_date = person['birthday'].replace(year=year)
+    description = event_config['description']
+
+    lang_params = {'language': event_config['language']}
+
+    if 'birthday_no_year' not in person:
+        description += ', %d' % age(person, year)
+
+    event = Event()
+    event.add('uid',         sha1(person['name'] + ' birthday ' + str(year)))
+    event.add('summary',     person['name'],
+              encode=True, parameters=lang_params)
+    event.add('description', description, encode=True, parameters=lang_params)
+    event.add('categories',  event_config['categories'])
+    event.add('transp',      'TRANSPARENT')
+    event.add('dtstamp',     datetime.datetime(
+        event_date.year, event_date.month, event_date.day))
+    event.add('dtstart',     event_date)
+    event.add('duration',    one_day)
+    return event
+
+
+def add_events(cal, birthdays, year):
+    for item in birthdays:
+        event = make_event(item['person'], year)
+        cal.add_component(event)
+
+
+def make_calendar(calname, timezone, birthdays, scale):
+    cal = Calendar()
+    cal.add('version',  '2.0')
+    cal.add('prodid',   '-//birthdays calendar generator//b4tman.ru//')
+    cal.add('calscale', 'GREGORIAN')
+    cal.add('method',   'PUBLISH')
+    cal.add('x-wr-timezone', timezone)
+    cal.add('x-wr-calname',  calname)
+    for year in range(scale['start'], scale['start'] + scale['length']):
+        add_events(cal, birthdays, year)
+    return cal
+
+
+config = load_config()
+birthdays = config['birthdays']
+
+event_config['language'] = config['language']
+event_config['description'] = config['events']['description']
+event_config['categories'] = config['events']['categories']
+
+parse_dates(birthdays)
+birthdays.sort(key=lambda x: x['person']['birthday'].strftime('%m.%d'))
+
+cal = make_calendar(config['calname'],
+                    config['timezone'], birthdays, config['scale'])
+
+if len(sys.argv) > 1:
+    filename = sys.argv[1]
+    write_calendar(cal, filename)
+else:
+    display(cal)