The American, who served as President of the International Softball Federation (ISF) for 26 years and was once WBSC co-President, passed away at the age of 90 on June 7.

"Every year on this date we all celebrate our passion and love for softball," WBSC softball chairman Tommy Velazquez said.

"Today we’re not only honouring our beloved sport but also paying homage to the memory of Don Porter, who passed away last Sunday. 

"He was the driving force behind softball’s inclusion in the Olympic programme and the globalisation of our sport."

World Softball Day is celebrated on June 13 because it was on this day in 1991 that the International Olympic Committee announced that women's softball would be included on the Olympic programme for the first time.

Women's softball duly made its debut at the Atlanta 1996 Games, with the United States winning the gold medal.

It appeared at the next three editions, with the US winning two more gold medals and Japan taking the title at Beijing 2008, but the sport has not made an Olympic appearance since.

Women's softball, along with men's baseball, is set to feature at Tokyo 2020 - now postponed until 2021 - but not at Paris 2024.

The ISF staged its first Softball World Championship in 1965 and the body was celebrating the 40th anniversary of the event when Porter proclaimed June 13 2005 the inaugural World Softball Day.

Before becoming ISF President, Porter was secretary general and helped to organise the first Softball World Championship.

He campaigned long and hard for softball's Olympic inclusion and was awarded the Olympic Order in 1997.

Porter helped establish the WBSC when the ISF and the International Baseball Federation merged in 2013, serving as co-President until 2014, when Riccardo Fraccari was elected President unopposed following Porter dropping out of the election.

Porter was awarded the Collar of Honour, the WBSC's highest recognition for people who contributed to the foundation of the worldwide governing body, in 2017.

World Softball Day celebrations are somewhat muted this year, with many countries still restricting what activities can take place because of the coronavirus pandemic.

However, Northern Territory in Australia is one place that has been able to mark it in style as the Darwin Softball League returned to action today.

New dates for the Men's Softball World Cup - set to be held in New Zealand in 2022 - were announced earlier this week.