How do I iterate date range with ModScript?

I would like to do something like this in ModScript with SBM 11.3 ....

for each day in Start_Date to End_Date-1

... do stuff

Start_Date and End_Date come from SBM "Date-Only" date/time fields. Reading them returns ISO8601 strings. I can convert that to a Variant Epoch secs value with Ext.DateToDbLong(). I want to avoid using CDate() or DateValue() because those appear to adjust the ISO8601 value to the Server's timezone. I'd like to use native chaiscript/Modscript types, but I haven't figures out how to convert that ISO8601 value into a chaiscript double or long int. I'm not sure if the TimeT type would work as a loop iterator, and the methods that make TimeT useful didn't show up until 11.4