They mean every night, as in each night. About 20 standard drinks in a bottle of vodka, so takes 18-20 hours to process all the alcohol before starting again. It's just about doable with a day job if you start as soon as you get home from work and don't have to drive in the morning. I know because that was me once.

This is why people with serious drinking problems find the "I drink a beer every night I must be an alcoholic" chat a bit offputting. And look, a bottle of vodka a day leaves some room for a few sober hours, so it's actually not as bad as the people who get withdrawal unless they stay topped up 24/7.