I’ve got my smart tariff downloaded ok, but noted that the dates on the data were just showing as “invalid date” - is there a way to fix this?
Octopus dates

Smk82 not sure what you mean by invalid date. Where does it show that, could you share a screenshot?
I tried to add a screenshot but no luck. If you scroll to historical data in the smart tariff card, below the bars, it just says invalid dates for each one

Smk82 if you mean the dates that show your usage, I believe this comes from Octopus using their API. Have you been with Octopus long?
Over two years.

Smk82 might be worth clearing your data from the card, then re-adding it.
You could also try plugging your info into the Octo Comparison site to see if that can pull your consumption through. https://octocomparison.co.uk/comparison
If still no joy seems like it might be an issue with Octopus, drop them an email and see if they can do something there end.