Hi, Can someone explain the layout/use of the timezone lists in DateTime.py or point me in the direction of a how-to etc. I would like to understand the layout of the _zlst and _zmap listings, and how to add new locations to it including Daylight Savings. What do these relate to and stand for... 'UT','BST','MEST','SST','FST','WADT','EADT','NZDT', 'WET','WAT','AT','AST','NT','IDLW','CET','MET'...etc Some of them I can recognise like New Zealand Std Time (NZST) but others aren't. Is there some reason these aren't provided with a full description like the list above it with... 'Brazil/Acre','Brazil/DeNoronha','Brazil/East', 'Brazil/West','Canada/Atlantic'....etc The same question for the Australian timezones... 'aest':'GMT+1000', 'aedt':'GMT+1100', 'aus eastern standard time':'GMT+1000', 'sydney standard time':'GMT+1000'...etc Thanks for any help. Richard