Hi K, There's always "Half Way To The Wall".........
That way you're only half wrong!!!
I count from the time of the last trade. If I were to decide on 30 day intervals between sequential buys and I traded next Friday (the second of Aug.) then I'd reset the clock for the second of Sept.
The Idiot Wave will most likely be close to the same level next week, meaning low risk for new money. I can't see far enough into the future to see next month. :-)