I have a related problem in Germany.
We often have sings saying 30 between 22.00 and 6.00 and the rest of the Day you are allowed to drive 50.
In my mind it shouldn't be to difficult to include multiple Speed limits depending on the Time of Day.
I think i speak for many Germans when i say that we are looking forward to it.

This would be a GREAT idea!

Also from Australia here, we have School Zones where the speed is lowered to 40km/hr during a few hours in the morning and a few in the afternoon.

I can see this variable speed limits being used in a huge range of situations. A fantastic ad-on to that idea is the addition of speed limits being varied during seasons. For example in winter, some of the snow road routes have their speed limited throughout.

Really needed in Germany. WME must have this functionality

In Australia we have variable speed zones too, this would also enable reports on school zone speed variations

I had a couple of fines before I found out that Waze isn't as correct as I thought it was.
On motorways in the Netherlands, you are allowed to drive 100 KPH in the day, 130 KPH after 19:00. Waze only tells you the speed limit for 130 KPH so maybe this can be a good feature to add.
Or at least make the speed limit 100, so it won't make you think you can drive faster while you actually can't.

In the Netherlands we have highways where during the day, you're only allowed 120 KPH, which is between 6:00 AM and 7:00 PM, outside those times the speed limit is set to the max limit (in this case 130 KPH).

Another example is in Germany (highway)roads sometimes during the day there is "no speed limit" and during the night there is (so reversed).

Adding this will help people know what the maximum speed is according to the time of day. Note this is not based on road-works, or temporary speed limits, but permament rules for the speed limits.

The editing interface should permit the addition of time-based variable speed limits to the map.

In NYC, speed cameras have been deployed around schools but are generally operational on "school days during school hours and one hour before and one hour after the school day".

Effectively this means the speed cameras are operational Monday-Friday from 7:30AM-3:30PM during the school year (and perhaps a 1-month summer school period.)

Perhaps there could be a way to attribute the known days/hours where these cameras are in operation so as to not trigger false alerts.

Second, while the road speed might be marked to 25/MPH, the speed camera enforcement is for vehicles traveling 35/MPH or higher. Perhaps the "excessive speed trigger" can be set to warn people only when they are traveling above the enforcement speed?

(At the time of writing, these speed cameras have been disabled for political reasons.)

In The Netherlands a lot of highways have time-dependent speed limits, and some have traffic-dependent speed limits. The fixed time-dependent speed limit (a lot have 120 or 100km/h during the day and 130km/h during the night) should be easy to implement. But an option to report live speed limits would also be great for the traffic-dependent ones.

It will be great to give an opportunity to the notificatiaon about temporary speed limits. It should be an warn with the start and the end of speed limit. To this function is neccesarly an option: what kind of speedalert is the valid in a case of temporary speed limit?