How long is too long to wait to pitch yeast?

Yesterday I brewed my first double batch, a robust porter and an American amber. Using the same yeast for both. I usually make my starter the night before I brew. Didn't get home in time Tuesday night to get it done, so I got up early Wednesday morning and mixed up the starter and got it going on the stir plate. By the time both batches were done the starter wasn't quite ready.

I sealed up both batches into carboys and let them sit overnight while the yeast did it's work in the starter. Pitching it today.

My question is: How long is too long to wait before I pitch yeast? I know that you want the yeast in there doing its thing before other beasties can take over, but what is your window?

I don't know how long is too long but I do know what you did is fine. I've waited longer than that with no problems.

Cubing the wort is very common practice here in Australia - google NO CHILL BREWING.

Wort is not chilled in the kettle but put directly into 20L plastic storage containers which of course have been sanitized. The very hot wort also serves to keep everything sanitary, cubes are filled and it is sealed up so no air in the container. It is not uncommon to store wort like this for months until need for fermentation.
Secret is fill the containers to brim with very hot wort and there is no worry about contamination.

Your asking how long will it take to get infected? In a perfect world, never. In this world something is going to eat that sugar, it's coming like a freight train.

I've gone about 36 hours w/ no problems.

My last dozen batches or so have all been pitched 12 - 18 hrs after flame out. But, they have been in a corny. No problems.