Will an existing timestamp without time zone value ever automatically change?

Question

For example, certain time values might auto change when the system time zone changes. Will a timestamp without time zone value that's already stored in the database auto change for any reason at all?

Answer 1

Neither timestamp (timestamp without time zone) nor timestamptz (timestamp with time zone) values will ever change by themselves. Only the display of timestamptz adapts to the current timezone setting.

Or you can display date and time for a given time zone with the AT TIME ZONE construct. And / or you can format it any way you like with various formatting functions.

The actual setting in your session is relevant for display, not the system time zone. Related:

• Ignoring time zones altogether in Rails and PostgreSQL
• Time zone storage in data type "timestamp with time zone"