Meteorologists, for example, likely have that date circled because it marks the opening of the Atlantic hurricane season.
Environmental alarmists likely have June 1 circled in fiery red as a reminder to keep harping on their belief that global warming is somehow to blame for the recent rise in hurricane activity.
We hope that red circle was drawn with something erasable.
That's because a respected and reputable research meteorologist has recently released a study that concludes global warming is not to blame for more hurricanes, or even stronger ones.
Members of the doomsaying crowd see it this way: Global warming heats the ocean, which creates prime conditions to create hurricanes.
Rightly skeptical climate experts attribute the increase in hurricanes to a natural multiyear cycle.
Now comes Tom Knutson, a meteorologist with the National Oceanic and Atmospheric Administration's fluid dynamics lab in Princeton, N.J. He used to be one of those very same doomsayers. In his former life a climate-change Cassandra, he even complained that his assertions about the dangers of global warming were being censored by the Bush administration.
Now, in his study based on a detailed computer model, he finds no credible link between greenhouse warming and hurricane increases.
That's the kind of objective scientific inquiry we need to truly understand the scope of our environment.
We don't know what the coming hurricane season will bring. But recent years have seen much less intensity and activity than feared.
Instead of scientists reflexively pointing fingers to a single man-made cause, they should look at all the causes -- and start hammering out solutions.