General directions for a timer circuit which will not use microcontroller and which can measure several hours needed
I know you specifically said that you did not want to use a microcontroller, but I think you should consider taking the plunge into the microcontroller world. Doing a timer like this is very easy to do on a very cheap micro since you don't need it to do anything special.

In general I have found that using a "complex" circuit of discrete components is usually plagued with minor errors in both design and construction that cause them to take a lot of time and money.