Time Complexity of Genetic Algorithms
Genetic algorithms are a metaheuristic and as such there is no general analysis that applies to all genetic algorithms at once (without being super loose). In general, when you are searching for information on the run-time of genetic algorithms, you will have more luck if you use the terms "convergence time", since that is the more common terminology. A good start on some formal techniques:

Y. Rabinovich, A. Wigderson. Techniques for bounding the convergence rate of genetic algorithms. Random Structures Algorithms, vol. 14, no. 2, 111-138, 1999. 

For more resources on formal treatments, consider the cstheory question: Provable statements about genetic algorithms.