Am I missing something? 1000 hrs /(24 hrs/day) = 41.67 days

And I don't think 'genetic algorithm' means what you think it means. All a GA does is try to find the max/min of some function. It is basically just hill climbing with a bit of randomness and a catchy name.

To find 'fishy' transactions you would use some sort of unsupervised machine learning algorithm to identify patterns/clusters in data (and that's starting an entirely different discussion).