Excel - principal plus interest minus mandatory RRIF withdrawal calculation | RRSPs and RRIFs | Discussion forum

I can't help you with the mysteries of Excel.
You can set the withdrawal date for whenever you like, in my experience, but it might be to your advantage to set it for the anniversary date if that gets you better return. It depends on the policy of the financial institution as to how they treat the interest on the portion subject to mandatory withdrawal.
No harm in planning ahead, but there is always the possibility that the rules could change between now and then.

In a sense, what you are saying is true, I think, kanaka, because in the current environment the mandatory withdrawal at age 70+ will always be higher than the interest earned annually.
However, I think the issue then becomes, what do you do with the money that you have withdrawn? If you need it for expenses, then of course it is gone. If not, you can reinvest it in non-registered allocation or move it to tax-free savings and perhaps not miss a beat with your compounding. Given that you would likely get a lower rate of interest in a series of 1 yr investments, you're probably still better off with the longer term, even though it goes in one hand and out the other - that is, unless interest rates go up over the next few years. I'm not betting on it. The pundits keep saying "next year", but they've been saying that for a few years now. I honestly don't think "the economy" can afford higher rates, even though I'd like to be receiving them. With the price of houses in the big cities in this country, you could cause economic collapse by raising the rates a couple of per cent, just through the effect on mortgages alone, which would almost double many people's interest payments on their loans! This would especially affect homeowners in the early years of their mortgages when the interest is the biggest chunk of the payment. I doubt any central banker wants to take that risk. But I digress.

I can't think of any reason not to do this, and have already started although I am not yet in the mandatory withdrawal age group.
Your decision could be influenced, I suppose, by your sense of your own longevity. If you're going to live past 84, then Gordon Pape says you should turn your Rif into an annuity because the payouts are less than the mandatory withdrawals and thus you pay less tax annually. Some people think you should do this a bit earlier. It can help with the clawbacks.
If TFSA contribs are allowed to increase significantly, which they might be, I would wonder if they might decide to ding RRSPs/RIFs a bit more somehow. This, I think, was Flaherty's idea, to encourage people to use TFSAs more than RRSPs, because it was widely recognized that most people weren't contributing to RRSPs, and the ones that were often had pension plans as well. So, if that line of thought is followed, it's logical to think that RRSPs could be phased out in future. I don't know, however, how that would impact withdrawals or taxation on withdrawals. I suppose that, for now at least, the government appreciates the extra tax it gets to take from the mandatory withdrawals. I can't see them giving that up.