  The unexpected development of cycle 24 emphasizes the need for a better way
to model future solar activity. In this article, we analyze the accumulation of
spotless days during individual cycles from 1798-2010. The analysis shows that
spotless days do not disappear abruptly in the transition towards an active
sun. A comparison with past cycles indicates that the ongoing accumulation of
spotless days is comparable to that of cycle 5 near the Dalton minimum and to
that of cycles 12, 14 and 15. It also suggests that the ongoing cycle has as
much as 20 \pm 8 spotless days left, from July 2010, before it reaches the next
solar maximum. The last spotless day is predicted to be in December 2012, with
an uncertainty of 11 months. This trend may serve as input to the solar dynamo
theories.
