Specifications for vector tiles loading? (both .pbf and metadata.json)

I cannot find any proper documentation anywhere regarding the specifications required for vector tiles loading (both .pbf and metadata.json).

I tried loading my own vector tiles & metadata that include a timestamp in ISO8601, but kepler.gl parses it as strings and it's not showing up in the filter.

Can someone point me to the right direction?

Edit 2:
I tried converting ISO8601 to unix timestamp and declare it as "number" on `metadata.json`. Kepler.gl parsed it as float and made it an available "field" in filter now.
"time", "date", "datetime" types don't seem to be available for vector times & metadata loading.
Can somebody help?