Standardizing data over time (not space) in ArcGIS Pro 10.8?

I am trying to standardise Standard Precipitation Index data and Vegetation Health Index data over time on a 0 to 1 scale. I was previously using the fuzzy membership function to standardise the data over space, but this was not reflecting the raw data appropriately, especially as the Standard Precipitation Index data has negative values which are of higher preference to larger, positive values.

I have tried the reclassify and rescaling functions but these have not proven to work either.