2000-02-16：实现“日期/时间大统一”。
25年前的今天（PostgreSQL 7.0 开发周期），一个实现了日期和时间支持的重大重构的补丁被提交。
commit 41f1f5b76ad8e177a2b19116cbf41384f93f3851 Author: Thomas G. Lockhart <lockhart@fourpalms.org> Date: Wed Feb 16 17:26:26 2000 +0000 Implement "date/time grand unification". Transform datetime and timespan into timestamp and interval. Deprecate datetime and timespan, though translate to new types in gram.y. Transform all datetime and timespan catalog entries into new types. Make "INTERVAL" reserved word allowed as a column identifier in gram.y. Remove dt.h, dt.c files, and retarget datetime.h, datetime.c as utility routines for all date/time types. date.{h,c} now deals with date, time types. timestamp.{h,c} now deals with timestamp, interval types. nabstime.{h,c} now deals with abstime, reltime, tinterval types. Make NUMERIC a known native type for purposes of type coersion. Not tested.