Unable to set receipt dates before 2020

[davidak]

What

I added a receipt from 2019 and could not set the correct date in the app. It works in the web interface, so i consider this a bug.

Steps to reproduce the behavior

1. Add receipt for price
2. Try to set a date from 2019

Expected behavior

If there is no official limitation for date, let the user set any date.

Screenshots

Smartphone model

• Device: Xiaomi Mi 11 Pro
• OS: Android 13
• App Version: 4.23.0

[monsieurtanuki]

Hi @davidak!

You're right, there's a date limit:

final DateTime firstDate = DateTime.utc(2020, 1, 1);

Which first date would make sense to you?

[monsieurtanuki]

cc. @raphodn @raphael0202

[davidak]

Which first date would make sense to you?

I don't know. What is the scope of the project?

What is relevant for inflation research?

Aesthetically speaking, maybe 1900? But there was probably bread sold in 1800? They did not have the same currency. They probably did not have receipts. Researchers probably have this information already archived.

[monsieurtanuki]

My 2 cents:

• There were 51 states in the UNO in 1945, vs 193 today.
• The pattern for barcode was filed in 1949
• We need an OSM shop, or an online shop
• Many European currencies are not supported since the Euro in 2002
• We're talking about an app that help users scan their receipts

@davidak Please feel free to attach here a proof image about a receipt with an identified shop that exists in OSM, a date, a currency, products and prices, that you'd like to add to Prices.

[davidak]

@monsieurtanuki very good points!

The german statistical federal agency has released a Consumer Price Index for each year since 1991 compared to 2020.

https://www-genesis.destatis.de/datenbank/online/statistic/61111/table/61111-0001

They also have an CPI for every federal state independently since 2005.

https://www-genesis.destatis.de/datenbank/online/statistic/61111/table/61111-0020

I don't know if earlier data is not relevant or does not exist. I feel like we could use 1990 or 2000. But a feeling of some random german person might not be good enough to set the scope of this global project.

They also have a price monitor since 2020 here for different categories of products.

https://www.destatis.de/DE/Themen/Wirtschaft/Konjunkturindikatoren/Preismonitor/Preismonitor.html#246992

Please feel free to attach here a proof

I had added this proof and fixed the date in the webinterface. But the product names are not distinct. They have one name for different kinds of frozen pizza. So i'm also unable to identify the exact product.

https://prices.openfoodfacts.org/proofs/113963

[monsieurtanuki]

@davidak Thank you for your proof. It may be incorrect:

• you paid 1,19 for one apricot
• you cannot be sure it's the same Bionella barcode. I know that my 5010477348678 muesli recently evolved into 5010477370396

They probably don't set a first date in the web app: I managed to go back to the 1st of January 1. I mean 0001. For the record it was a Monday, a good day to start the week.

The process of app upgrade is very slow anyway.
I would advise you to set your "old" proofs with the web app, meanwhile.

I don't believe old proofs are what Prices are made for, but I'm open for fresh inputs on the subject, especially about a decent minimum date.

[davidak]

It may be incorrect:

you paid 1,19 for one apricot

it was a bowl of apricots, probably 500g. this was automatically detected. i deleted it

you cannot be sure it's the same Bionella barcode

well, you can never be sure if you don't scan the barcode every time

the image looked like the product i bought. the other barcode on OFF is from france, while the one i used is from germany. so it is at least the same product

I don't believe old proofs are what Prices are made for

I thought these receipts are a treasure and the most useful data, as it can show price changes over time. But with this specific one, most products can not be identified.

I'm generally unsure about the purpose and usefulness of Open Prices. I will discuss that elsewhere.