This is not a complaint but just an anecdote that we bought bread in a bake shop that offered a 50% discount on their bread which were baked on that day. However, we ate the bread for breakfast on the next morning and we noticed the taste not to be fresh anymore. I told everyone to toast the bread if they are not satisfied with the taste. On the second morning, there was a trace of mold in the bread and it cannot be denied that the bread is not 2 days old only. This is a caveat to be careful of bread sales for they may be selling old bread.
Here in the UK sometimes the best times to visit a bakery or supermarket is just before it closes as that's when all items that have been baked that day are on offer. In the past I've bought a few items and they have lasted for a couple of days past there date, other times I've woke up and in the morning they have been mouldy so I guess you just have to take that risk. For the discount you are getting though, sometimes upto 75% you can't really complain too much if you only get to eat part of what you've bought.
Unless it's really hot and humid where you live, bread should not generally go moldy in one day. I think you are right that it was more than one day old. They should be honest about the date, so they don't harm their reputation. I've bought bakery bread that was marked down at the end of the day or first thing the next morning, and it's never gone bad in one day. It might start to mold after two days, when our humidity is high. I usually keep it in the fridge to avoid this and just warm it up before serving. You do have to watch some discounts though. Some stores seem to only put stuff on sale if it's out of date or if there is something wrong with it. People pick up on that kind of thing quickly, especially savvy shoppers.
Here in the UK I don't think we have to worry too much about buying out of date goods, and especially from the big name chains as they have a reputation to try and maintain and so it's simply not worth them risking it. You might get the odd item that as been overlooked but I don't think any store is going to do that on purpose. Health and safety is a big deal here now and any stores that don't adhere to the strict guidelines in place get punished quite significantly. No popular bakery or supermarket want's to be known as the one that's selling out of date goods so in this instant I think the rules and regulations put in place actually benefit the consumer.
