Thanks for sharing such a great post
I'm glad you like it, but there are some issues to discuss beyond the general one of what aspects of it I'm not fully thinking through.
One is whether it is possible to honor the deposit date on electronically-saved money. E.g. if you spend less than you deposit, you could say that all the withdrawals from an account deplete the most recent deposits first, which would leave the earliest deposits untouched.
That would allow you, just by means of your electronic bank-deposit history to cash in on aging untouched deposits. E.g. say that you have 2017 or 2014 dollars in your account that have never been spent; you could then use those to purchase 2020 dollars at the inflation-adjusted rate. Once deposited money is electronically transferred, however, it would not be transferable as dated money, unless of course banks agreed to keep track of different currency issue years as they passed between accounts.
If you could sell those 2014 deposits for their face value plus whatever inflationary appreciation is attributed to them, would governments/banks be willing to back aged currency in this way, i.e. by buying deposits from earlier years at an appreciated rate? Idk, why or why not?
If not, then the question becomes whether it is better to save money in cash than in electronic accounts. If people realized that their savings would appreciate proportionally to inflation by saving it in cash bills with physical/ink numbering and dating, that would change banking to involve a lot more vaults, safety deposit boxes, etc.
If, however, government and banks would just agree to recognize the electronic date stamp on deposited money as the equivalent of an issue date for printed currency, then it wouldn't matter if you saved actual bills or just maintained a regular electronic bank account.
LARGER ECONOMIC ISSUES
The economic issues that could flow from this are what really make it an interesting concept, though, imo. Just think about currency markets. If each currency would have different exchange rates for each year of currency, a currency's overall strength could be influenced by the strength of its older years of currency.
So, for example, let's say 2010 US dollars are trading at 2020$1.20 due to 10 years of 2% inflation and 2010 Euros are trading at EU1.10 because of lower inflation (just examples since I don't know the actual inflation histories of these currencies off hand); then investors could buy more 2010 Euros and drive up the value, which would allow savers of Euros to cash in even more on the low-inflationary stability of that currency.
Likewise, if a currency has a relatively high inflation rate in the present, investors could also buy up older years of that currency in anticipation of higher inflation-proportional yields. By doing so, they would gain the ability to exchange the older currency for larger quantities of the present-year currency, which would effectively neutralize the inflationary value-loss of investing in that currency if it didn't have inflation-adjusted pricing for older years.
This is all a bit confusing, so I'm still not sure if there are scenarios that could occur that would cause the value of older currency years to crash. E.g. what if inflation was very high in a given currency and so older years of that currency were being valued very high. That would likely result in overvaluation and investors would avoid such a currency, expecting its government to fail at maintaining past-year buybacks at the inflation-adjusted rate. In that case, all years of the currency might crash in value, not just the most recent years issued.
So I guess this system of appreciating the value of currency by issue/deposit year would only work for relatively stable currencies with relatively low gradual inflation rates.