If longer duration of upgrade events isn't possible, I would appreciate a further advance notice. I miss many of the upgrade events just cause my workers are already busy -- sometimes even on something I just sent them to a day before!
This is a band-aid approach; the long time-to-upgrade times made sense long ago when there were fewer Ages (when, say, the max age was Industrial...), but it makes zero sense today. Folks should have a solid Industrial base in 2-3 weeks today to increase the user base and fun. Always keep longer times in the last few ages but make the earlier ages quicker. The choice is simple: have folks reach Industrial Age and enjoy the game (and yes, even start spending more), or have them quit early at say Classical Age. It makes sense for both users and business.
once, months ago, I suggested to make upgrades of all buildings of a given type last the same time FOR ALL AGES!
i.e. Mortars. All levels take 4 days
Redoubts. All levels take 4 days
Antitank guns All levels take 3 days
Garissons All levels take 3 days
Farms All levels take 2 days
Caravans All levels take 2 days
Airport All levels take 5 days
Factory All levels take 5 days
This makes the game almost equally long and spreads the player base more evenly among ages but the player has the feeling that upgrades are not there to break his nerves and test his patience. Boredom is much less using that method. And we all know that we need x amount of days for a certain upgrade. Not as it is now, that we have reached 15-16 days for SA buildings which is ridiculous
Upgrade discounts usually start on a Friday. So if a few of my upgrades just finished, I'll wait a few days to see if there is a good discount available. Plus they usually rotate what is being discounted, I just follow the discount path with the ones I really want/need.