Time types that supports positive and negative infinity. Also includes new time parsers and printers with better performance than GHC's time package. The parsers only understand the specific variant of ISO 8601 that PostgreSQL emits, and the printers attempt to duplicate this syntax. These likely have problems and shortcomings. Some that I know of:

1. Timestamps with time zones before 1883-Nov-18 12:00:00-05, the moment Standard Railway Time went live, cannot be parsed. This is because PostgreSQL will emit 1883-11-18 12:03:57-04:56:02 instead of 1883-11-18 11:59:59-05, and the timezone parser is incomplete. Timestamps without time zones do not have this problem.
2. Dates an times surrounding 1582-Feb-24, the date the Gregorian Calendar was introduced, should be investigated for conversion errors.
3. Points in time Before Christ are not also not supported. For example, PostgreSQL will emit 0045-01-01 BC for a value of a date type. This is the year that the Julian Calendar was adopted.

However, it should be noted that the old parsers also had these issues.