Friday 26 December -
St. Stephen's Day (public holiday in Alsace, Austria, Andorra, Catalonia, Croatia, the Czech Republic, Germany, Hong Kong, Italy, Ireland, Luxembourg, Poland, Slovakia and Switzerland);
Second day of Christmas (Western Christianity. Public holiday in the Netherlands, Poland, Norway)
Monday 11 May -
Mother’s Day (Anguilla, Antigua and Barbuda, Aruba, Australia, Austria, Bahamas, Bangladesh, Barbados, Belgium, Belize, Bermuda, Bhutan, Bonaire, Botswana, Brazil, Brunei, Canada, Cambodia, Cayman Islands, Central African Republic, Chad, Chile, China, Colombia, Congo, Dem. Rep., Congo, Rep., Cote d'Ivoire, Croatia, Cuba, Curaçao, Cyprus, Czech Republic, Denmark, Dominica, Ecuador, Equatorial Guinea, Estonia, Ethiopia, Faroe Islands, Fiji, Finland, Germany, Gabon, Gambia, Greenland, Ghana, Greece, Grenada, Guyana, Honduras, Hong Kong, Iceland, India, Italy, Jamaica, Japan, Kenya, Latvia, Liberia, Liechtenstein, Macau, Malaysia, Malta, Myanmar, Namibia, Netherlands, New Zealand, Pakistan, Papua New Guinea, Peru, Philippines, Puerto Rico, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, Singapore, Sint Maarten, Slovakia, South Africa, Sri Lanka, Suriname, Switzerland, Taiwan, Tanzania, Tonga, Trinidad and Tobago, Turkey, Uganda, Ukraine, United States, Uruguay, Vietnam, Venezuela, Zambia, Zimbabwe);
Mamertus, the first of the Ice Saints;
International Dixieland Festival Dresden (starts on the second Sunday in May, but sometimes the date can vary);
Genusszeit in Saarbrücken (starts on the second Sunday in May)
Saturday 15 August -
Feast day of the Assumption of Mary (Christian feast day, one of the Catholic holy days of obligation a public holiday in Austria, Belgium, Benin, Bosnia, Burundi, Cameroon, Chile, Colombia, Croatia, Cyprus, France, Germany, Greece, Guatemala, Hungary, Italy, Ivory Coast, Lebanon, Liechtenstein, Lithuania, Luxembourg, Macedonia, Madagascar, Malta, Mauritius, Monaco, Paraguay, Poland, Portugal, Romania, Senegal, Seychelles, Slovenia, Spain, Switzerland, Togo, and Vanuatu);
Dachau Folk Festival;
European Elvis Festival;
Mombach Rhine Festival;
Draiser Kerb;
Dresden City Festival;
Echelon Festival;
Rudolstadt Bird Shooting;
Leipzig Water Festival;
Stoppelmarkt in Vechta;
Rüsselsheim Kerb;
Kreuznach Fair;
Autumn Fair in Ochtrup;
Säubrennerkirmes in Wittlich;
Old Town Festival in Wernigeride;
Gifhorn Old Town Festival;
Wittenberge Town and Harbor Festival;
Münster Mittendrin, City Festival;
Aurich Town Festival 
Remind me of calendar occasions
