Nations and empires have used the gold standard for thousands of years.
Crack open David Graeber’s “Debt: The First 5000 Years”. He’s an anthropologist who spent his career investigating this theory, and he found it wanting. Hardly the first, but probably a more fun read than Thomas Piketty or Milton Friedman or Adam Smith. Nations and empires didn’t use gold specie until fairly recently in human history. Most of human civilization revolved around different types of credit and debt, typically enumerated in volume of agricultural produce.
Wheat/corn/rice, fish, olive oil, and salt were the most common standards of exchange. Gold was ornamental, but far too little of it existed to circulate as common currency or even reserve currency. It wasn’t until the colonial era and the mass exploitation of Africa, East Asia, and the Americas that European Banks had a large enough surplus gold reserve to treat it as coinage.
So you’re talking at best hundreds of years, and even then only within the handful of European powers capable of plundering the gold reserves of foreign nations on a global scale. And even that only got these countries from the 15th to the 18th century before the system started breaking down.