Atari PONG C-100 Release Date?

[Atari PONG C-100 Release Date?]

Hi I'm a video game collector who is trying to record the release dates for different systems, including the Atari PONG, Model C-100. I can't find the release date, including the month and day. If any of the experts here know it or where I can find it, any help would be much appreciated.