Hey patriot - long time no chat!
The way I handle this is by creating a floating point node custom property with the GMT offset for each node (e.g., -7 for PDT, -5 for CDT, and -4 for EDT). Then when I create the report, I limit the rows (in SWQL or SQL) to those where the hour is >= (dateTimeField + customPropertyUTCOffsetField) if the dateTimeField is UTC already (as it is with availability). Boom, you have a timezone aware report! If you want a hand with the particulars, give me a shout and we can hop on a GoToMeeting and chat about it.