I really think that all you have to do is adjust the date in the top right corner of your recipe page. So my calendar isn't filled with beers I haven't brewed yet I just enter a random date and change the date after I actually brew.
What I do is keep the date that I write the recipe, then when I brew that recipe I copy it into the brew log and change the date there. That way when I brew the same recipe several times, I have separate instances with different notes and dates.