Father's Day
Father's Day was not celebrated in the US, outside Catholic traditions, until the 20th century. As a civic celebration in the US, it was inaugurated in the early 20th century to complement Mother's Day by celebrating fathers and male parenting.
After Anna Jarvis' successful promotion of Mother's Day in Grafton, West Virginia, the first observance of a "Father's Day" was held on July 5, 1908, in Fairmont, West Virginia, in the Williams Memorial Methodist Episcopal Church South, now known as Central United Methodist Church. Grace Golden Clayton was mourning the loss of her father, when in December 1907, the Monongah Mining Disaster in nearby Monongah killed 361 men, 250 of them fathers, leaving around a thousand fatherless children. Clayton suggested that her pastor Robert Thomas Webb honor all those fathers.
National Grandparents Day
The celebration was introduced to the UK in 1990 by the charity Age Concern. It has been celebrated on the first Sunday in October since 2008, although it is not widely advertised and has not been as commercially successful as Mother's and Father's Day. Businesses specialising in gifts and greeting cards have started merging the respective grandparents days with Mother's Day and Father's Day to try to boost sales.