|Shown on the right is a detail of the last 4
of our Sun's solar cycles. The Solar cycle displays a record of the
sunspot number vs. time. Notice that two subsequent solar cycles are not
well separated and uniform. The time of lowest sunspot number is not well
defined, having many days with a sunspot number of 0. Often one can have
sunspot groups from the old and the new cycle on the Sun at the same time.
Due to such issues with cycle date identification, the start of a new cycle
is stated with an uncertainty of one or two months.