The interviews were conducted over several days in 1977 and shown in four 90-minute programmes in various countries in May of that year, nearly three years after Nixon’s resignation.
The first to be broadcast was on Watergate, second on Nixon and the world, third on war, fourth on Nixon the man. Frost himself funded them or got private money, John Birt produced them, and they were syndicated in the US and worldwide. Nixon was paid $600,000 and a share of the royalties. Here’s the Watergate interview: