https://www.overshootday.org/newsroom/press-release-july-2023-english/
In an unprecedented collaborative endeavor, Slovenia's Ministry of Environment, Climate and Energy, in partnership with Global Footprint Network, announces a critical date for the planet: this year’s Earth Overshoot Day, lands on August 2nd.
From the article, because it explained it much better than i was going to:
The date, calculated by Global Footprint Network each year using National Footprint and Biocapacity Accounts data, marks the point when humanity’s demand for biological resources exceeds the Earth’s capacity to regenerate them within that year.
So basically, lets say 1000 tons of coal is formed every year (this is not a real number, its a hilariously high overestimate), “Earth Overshoot Day” marks the day we actually use up that years resources. So if that day is Aug. 2nd, that means we already used the 1000 tons that would have formed that year, on that day.