I was able to do

return json.dumps(response,default=str)

default=str handled some date stuff that wasn't parsing correctly.  This returns a raw string that can be s obj={}.%FromJSON(rawJson)

Now I'm trying to deal with a Python stream . . . that builtins.help method is helpful.

I tend to use $SYSTEM.SQL.Functions.DATEADD()

You can use this to add seconds, minutes, hours, days, etc. to  date.  The date/time should be ODBC e.g "2025-05-21T14:52:47.986"

There may be other ways, but this is how I do it to deal with UTC offsets.  

USER>s time=$tr("abcd-ef-gh ij:kl:00","abcdefghijkl",20250518144529)

USER>w time
2025-05-18 14:45:00
USER>s time=$SYSTEM.SQL.Functions.DATEADD("hh",-6,time)

USER>w time
2025-05-18 08:45:00