CREATE TABLE table_48398 ("Region" TEXT, "Date" TEXT, "Label" TEXT, "Format" TEXT, "Catalog" TEXT)

When did the United Kingdom format a stereo LP?
SELECT "Date" FROM table_48398 WHERE "Region" = 'united kingdom' AND "Format" = 'stereo lp'
SELECT "Date" FROM "table_48398" WHERE "Format" = 'stereo lp' AND "Region" = 'united kingdom'