Where you derived your discretionary income, it is possible to figure out your probable date of reaching your accumulation target. This is because, you choose your DCA approach carefully, date and amount.
I don't like the idea of using a specific time as the main focus to accumulate bitcoin, because the price of bitcoin is fluctuating and the quantity of bitcoin that you bought with "$100 today, will be differ from what you will buy in a month time because as a bitcoin investor, you need to continue buying both at the bear and the bull run and in all market condition. How is it now possible for you to reach you bitcoin target within your own given date. DCA only helps you to keep your bitcoin accumulation ongoing overtime but you cannot know the specific time that you will reach your bitcoin target, only if you are using a specific number of years as your target and not the quantity of bitcoin that you are accumulating as your bitcoin target.
If you use a specific year in which you will use to accumulate bitcoin, it will limit you from accumulating a good size of bitcoin because when the time reaches, you will stop accumulating bitcoin because you don't have a bitcoin target.