Roll-over of NNS voting rewards

Background & goal

The automation of exchange rate proposals is planned to be released in May ‘23.
Post this release, on some days (in particular on weekends) no NNS proposals might be submitted. Previously this was not possible as exchange rate proposals were submitted every 10 minutes.
As a consequence, there might be days during which no NNS proposals will settle. Since the distribution of NNS rewards is linked to the ballots of settled proposals, on those days no rewards are distributed. Rather, rewards will roll over to the following day.
On this page the roll-over mechanism is explained.

For any given day t_0 the NNS determines the total amount of available rewards R(t_0) for that day as a function of total supply and the voting reward function. For further background information on voting rewards see here.
Now assume that on day t_0, no proposal settled and thus no rewards could be distributed.
As a consequence, the NNS will roll over the rewards to the following day t_1. This means that on day t_1 a total amount of R(t_0) + R(t_1) is available for distribution.
If at least one proposal settled on day t_1 then this triggers a reward distribution. Otherwise rewards will again roll over to the following day and so on.

The NNS dapp will provide users information about the last time voting rewards were distributed, as you can see from the below screenshot.

If the indicated date is more than one day in the past, then NNS rewards are currently rolling over.