This will affect subsequent operations and conversions from TIMESTAMP to TIMESTAMPTZ - just make sure to get it right.Īfter you have converted all timestamps to TIMESTAMPTZ, server or client timezone setting (which defaults to current operating system timezone setting) is only useful for display purposes, as data manipulation will be always correct. If conversion does not work correctly, you can temporarily set timezone for current session (you need it only for conversion purposes) using statement like (use it before ALTER TABLE. You should be able to convert your existing TIMESTAMP columns into TIMESTAMPTZ using something like: ALTER TABLE mytable ALTER COLUMN old_tstamp TYPE TIMESTAMPTZīefore doing this, you should experiment on small dataset or maybe small test table on how conversion from TIMESTAMP to TIMESTAMPTZ is really working for you such that time zone information is preserved on your data. This allows you to always manipulate and display these columns correctly, no matter what current server or client timezone setting is. TIMESTAMPTZ stores both timestamp in UTC and timezone in which timestamp was originally written to (like CST, PST or GMT+6).