Mother's Day in the United States (and, I'm assuming, Canada) has its origins in the 19th century pacifist movement: Ruth Rosen explains:
...The women who conceived Mother's Day would be bewildered by the ubiquitous ads that hound us to find that "perfect gift for Mom." They would expect women to be marching in the streets, not eating with their families in restaurants. This is because Mother's Day began as a holiday that commemorated women's public activism, not as a celebration of a mother's devotion to her family.
The story begins in 1858 when a community activist named Anna Reeves Jarvis organized Mothers' Works Days in West Virginia. Her immediate goal was to improve sanitation in Appalachian communities. During the Civil War, Jarvis pried women from their families to care for the wounded on both sides. Afterward she convened meetings to persuade men to lay aside their hostilities.
In 1872, Juulia Ward Howe, author of the "Battle Hymn of the Republic", proposed an annual Mother's Day for Peace. Committed to abolishing war, Howe wrote: "Our husbands shall not come to us reeking with carnage... Our sons shall not be taken from us to unlearn all that we have been able to teach them of charity, mercy and patience. We women of one country will be too tender of those of another country to allow our sons to be trained to injure theirs"...
I haven't yet seen it (Ottawa politicians aren't awake yet), but undoubtedly sometime today we'll hear Mother's Day invoked in some bit of smarmy nonsense romanticizing the adventure in Afghanistan, which of course is the exact opposite from the intent of the women who created the holiday.