Finding out about the dates of table modification

I've moved happily from MySQL to Postgres but miss one really good feature of MYSQL: the table of tables that let you use SQL queries to find out metadata about your table. Thus looking at the table of tables and sorting it by last change, lets you quickly look at the most recently modified table. Which is really useful if you have a bad memory, as I do, and can't remember the name of a particular table that I worked on last Wednesday.

Are those capabilities hidden somewhere in Postgres? There isn't an obvious section in the documentation. At least I can't find it.

Martin Mueller
Professor emeritus of English and Classics
Northwestern University