Ah, right. We don't have access to the config by the time the push api is initialised. One way to fix this would be to put this line in the `.init`: https://github.com/praekelt/go-di/blob/feature/push-messaging/src/base.js#L38

Another way (that's maybe a bit safer) would be to put something at the top of `PushMessageApi` that looks something like:

```javascript
app.on('setup', function() {
  return self.init();
});

self.init = function() {
  self.calculate_push_dates();
  ...
};
```