On sale date based on house ads in the previous issue of The Funnies which state that this issue was expected to be on sale Tuesday February 8th. Note that there is conflicting information in The Funnies #17 regarding the expected on sale date of issue #18. There are three ads indicating Thursday January 27th and eleven ads indicating Tuesday February 8th. Since it is more likely that the issue was delayed during production, the February 8th date is believed to be the more accurate one.
Indexed from scanned copy at http://digitalcomicmuseum.com