Not a question I have seen asked or answered before, but my sense would be that it should work by calling at 9 a.m. For example, you could do that addition anytime after 8 a.m. if you had other points from another resort that you did not use when making the first reservation at 8 a.m. OTUPs would seem to fall within that same concept as long as the original reservation was made at 7 months out. Moreover, the only reason you cannot use OTUP points until 9 a.m. is simply because you have to call to get and use them because the online reservation and modification system is not set up to deal with the purchase and use of OTUPs. Thus, you need to wait until 9 not because there is any particular rule against using the points exactly 8 a.m. but only because of the inadequacy of the online system. When you attempt to do it, let us know what happens.