Operation Market Garden

Operation Market Garden Anniversary is still remembered with parachuting and dedications on this day. (Netherlands)

Marathwada Liberation Day

Marathwada Liberation Day (Maharashtra)

Heroes' Day

Heroes' Day (Angola)

Constitution Day and Citizenship Day

Constitution Day and Citizenship Day, observed on the previous Friday if it falls on a Saturday, the following Monday if on a Sunday; and the beginning of the Constitution Week (United States)

September 17 (Eastern Orthodox liturgics)

Christian feast day:
September 17 (Eastern Orthodox liturgics)

Zygmunt Szczęsny Feliński

Christian feast day:
Zygmunt Szczęsny Feliński

Socrates and Stephen

Christian feast day:
Socrates and Stephen

Satyrus of Milan

Christian feast day:
Satyrus of Milan

Robert Bellarmine

Christian feast day:
Robert Bellarmine

Lambert of Maastricht

Christian feast day:
Lambert

Hildegard of Bingen

Christian feast day:
Hildegard of Bingen

Stanislaus Papczyński

Christian feast day:
Stanislaus Papczyński

Beatification

Christian feast day:
Blessed Cecilia Eusepi

Ariadne of Phrygia

Christian feast day:
Ariadne of Phrygia

Albert of Vercelli

Christian feast day:
Albert of Vercelli