Issue on page /example_era5.html

To predict weather data we need to provide some historical data in the format which is mentioned in this link:
Example: Predictions for ERA5 — Aurora: A Foundation Model of the Atmosphere
But one item that I need to set in meta data apart from lat and long is time which I believe is forecast time.
metadata=Metadata(
lat=torch.from_numpy(surf_vars_ds.latitude.values),
lon=torch.from_numpy(surf_vars_ds.longitude.values),
time=(surf_vars_ds.valid_time.values.astype("datetime64[s]").tolist()[i],),
atmos_levels=tuple(int(level) for level in atmos_vars_ds.pressure_level.values),
),
but why would I want to forecast weather in the past, I already know what the weather was in the past and in fact I am providing that to model. I expect the model to be able to forecast weather data in future let say at lest say 1 hour from now. but when I pass any forecast date in future, or even in last few days it says it can forecast data 7 days ago or something. What am I missing?

Start with example_era5.html and the Metadata construction using valid_time and time. Reproduce the behavior with historical and future timestamps, then trace how the model interprets the supplied time. Done means the expected forecast-time behavior is established and the example or implementation clearly handles it.