Hi Zopistas: Last October 26th. here in Mexico we changed to the non daylight saving time period of the year. Some Zope applications that rely on DateTime started having trouble nevertheless they worked perfectly without a glitch during the DST months. The DTML methods use DateTime to build a date and later on, query a PostgreSQL table. This query involves building the date as: <dtml-call "REQUEST.set('fecha_final',_.DateTime(_.str(mes_fin)+'/'+_.str(dia_fin)+'/'+_.str(year_fin)).latestTime())"> The above code worked fine when in DST, now (not in DST) it adds a timezone like: '2003/10/28 23:59:59 US/Central' which causes a bad date external representation error coming from the DB. Previously (while in DST) where was no time zone added in the function call depicted above. The actual trouble is with DateTime working in DST periods vs and working in a non DST period. Can anyone be so kind to explain this behavior and a hint on the fix.? I have seen on the lists references to "bugs" on DateTime as old as year 2000 but no recent references to DateTime issues like thie one. Per your info, CST and CDT (American Central Standard/Daylight Time) both work ok for our purposes as we are in that same time zone here in Mexico City I am running Zope, binary release 2.6.1, upgraded to 2.6.2 on RedHat Linux 7.3 Your help and comments are greatly appreciated. Thanks in advance. Felipe Barousse