Up until a few years ago, unclaimed property reporting was pretty well divided into two different "seasons." The "Fall" reports (in a majority of state), which were generally due on October 31 or November 1; and the "Spring" reports (in a minority of states, but including such notables as Delaware and New York), which were generally due in the March to May timeframe.*
In the past few years, possibly in response to a desire to increase revenue, a few states moved their unclaimed property reporting and remittance dates to July. In particular, the reporting deadline in Michigan is now July 1 for property reaching its dormancy period as of March 31. Likewise, in Texas, unclaimed property reports are likewise due on July 1.
Thus, make sure that you don't forget about the "Summer" states as well.
* The dates above are the "general" reporting dates for most companies. In many states, life insurers and other holders might have holder-specific deadlines.