epoy2...we have the same NOA2 approval dates as well.. however, my wife is in Brazil.
The "validity dates" of the petition approval, a 4 month period of time during which the fiance(e) must complete the requirements for the visa. (May not be on every approval notice, but that doesn't mean there is time to waste). Note: This validity period may be extended at the consulate if needed.
Good luck and congrats!!