Hey,
I've noticed that it adds some of my commits to Wikimedia repos to my
calendar and sometime it doesn't.
If you commit using different git email/name/whatever, then GitHub will not recognize that as you unless you first do the needed config steps. This is true for all such git using services that I am aware of.
Cheers
-- Jeroen De Dauw - http://www.bn2vs.com Software craftsmanship advocate Developer at Wikimedia Germany ~=[,,_,,]:3