We run a job once a day to reset these totals to
0 for everyone exactly at UTC midnight, unfortunately when deploying network-wide changes to fix associations permanently some servers went absolutely batshit crazy due to a few race conditions. Our status dashboard looked like a Christmas tree for the better part of a hour. Hopefully though, you saw very few errors during this.
The reputation dropdown is driven off of 5 columns in the database from your user record:
ReputationYear. The way we maintain these is incredibly simple, a trigger. When
Reputation changes, that same delta is applied to all the other columns. When the interval rolls over, the job running at UTC midnight resets whatever intervals are changing to 0 for everyone in a simple update.
Due to the server farm FREAKING THE HELL OUT, that didn't happen. Honestly, it's just not worth fixing IMO, since it only affects the day interval and will fix itself tonight in the rollover.
If it's that important to people we can fix the totals for today, but unless there's a large cry to do so, I'll spend time on bigger fish today (e.g. showing actual rep change from when a user is deleted in a sensible way, or post migrations as "migrated" instead of "removed" in the rep history).