A bar-tending/drinking term:
When there is exactly as much in the liquor or mixer bottle as is needed in the glass(es), as if by accident or fate.
When a bottle is emptied into a glass without necessarily over-pouring, or making a drink too strong.
When you get out a shot glass, grab the required bottle, pour, filling the shot glass perfectly while emptying said bottle simultaneously; this is drinkronicity.
The bottle then must be discarded or replaced.
May also apply to mixed drinks in proportion.