I work a rotating shift and never drank before the day shift, I made up for it after work. Though there were times when I was still a little "buzzed" 'til 10 or 11 am. I didn't drink before my eve shift, but had 4 - 6 beers by myself after. The midnight shift was different. I "needed" 4 or more beers to get to sleep, usually 4 or 5 hours before my shift started. I tell myself that it would just be before the first shift, just to get into a different sleep pattern, then I'd stop. But I found myself drinking again for the rest of the shift. Then back to days off/day shift drinking. I can't tell you how long ago that started.