Hi everyone! My name is Alex Ryan and I’m an engineer at Asana. I’m here to help explain why we haven’t made this feature yet.
Right away I want to say that we hear your feature request loud and clear. We all use Asana ourselves every day, and this is a great product opportunity that we’ve been aware of for a while.
So the reason we haven’t built it is not that we haven’t thought of it, it’s that it’s actually really hard. Partly because it’s a surprisingly complex problem in general, and partly because of technical decisions we made in the past. Last year one of our engineers wrote a 3,000-word technical design document about how we could send notifications for due times, and it was circulated internally and reviewed by some very bright engineers. We have LOTS of tasks about it.
To be entirely candid, we don’t have a team actively building this right now. I know that’s not what you want to hear and I wish I could say we did, but the truth is we have a finite number of engineers and each quarter we have to make really tough decisions about what’s going to get built and what isn’t. So far, in part because of the disproportionate amount of work it would require, this hasn’t been the most leveraged thing we can put our engineers to work on.
You can rest assured that we’re always listening to your feedback, even when we aren’t acting on it right away 
. I wish I had better news to share, but we will get there eventually (and in the meantime, there have been some really clever workarounds in this thread!)