During what period were the songs for Metallica's The Black Album written?

The songs for Metallica's The Black Album were written in two months during mid-1990.

James Hetfield and Lars Ulrich wrote most of the material, often composing together at Ulrich's house in Berkeley, California. Guitarist Kirk Hammett and bassist Jason Newsted also contributed ideas. Newsted, for example, wrote the main riff for “My Friend of Misery,” which was initially intended to be an instrumental.

Some ideas originated during the Damaged Justice Tour, which supported ...And Justice for All. The band then developed the material before recording began in October 1990. Four demos—“Enter Sandman,” “The Unforgiven,” “Nothing Else Matters,” and “Wherever I May Roam”—were recorded on August 13, 1990.

The short writing period is often confused with the much longer recording process. Recording, overdubbing, mixing, and production continued into June 1991. Thus, the songs were written quickly, but the finished album took many additional months to complete.