[Question] Historical forecasting: Are there ways I can get lots of data, but only up to a certain date?

Suppose I wanted to get good intuitions about how the world works on historical timescales.

I could study history, but just reading history is rife with historical hindsight bias, both on my own part, and even worse, on the part of the authors I’m reading.

So if I wanted to master history, a better way would be to do it forecasting-style. I read what was happening in the some part of the world, up to a particular point in time, and then make bets about what will happen next. This way, I have feedback as I’m learning, and I’m training an actual historical predictor.

However, this requires a strong limit be enforced on the materials I’m reading: no information about “what’s going to happen” can leak backwards. And unfortunately, this is kind of standard in history books. Usually, the author talk about how events are leading towards other events that they know will occur.

Is there some databases (or something), where I might be able to read a wide number of primary sources and economic /​ socioeconomic indicators (like the amount of pottery fragments, average skeleton size, how far specialized goods traveled, how much money was in circulation, the literacy rate, etc.), but which will only show me data up to a certain date, with a strong constraint of not accidentally seeing spoilers?