world meaningful date time input

I've got an application brewing that gathers the following data:
location (lat/lon)
time (no time zone)
date. (no time zone)

The eventual goal is to be able to search chronologically using timestamps for the data anywhere in the world, from any location, using local time as a reference for any future date and time.

From the (lat/lon) it's possible to get:
named time zone
standard time zone offset (non dst)
by some special web services, get dates and amounts of
day light savings time

From there, it could possible to combine all the datums and create a timestamp with timezone (i.e. it's stored in absolute time (in seconds) relative to GMT)

Any easier way to do this?

Dennis Gearon

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