Some reports indicate that Phelps first met Smith on Dec 21; others give Dec 24 as the date.
Evidence that Phelps was a former Mason is given in the following quote from the Niagara Courier Vol. V, Lockport, NY, August 30, 1831:
‘The Masonic editors seem to be somewhat elated because Mr. W. W. Phelps, late editor of the Ontario Phoenix, an “Anti-Masonic newspaper”, as they are sure to designate it, has joined himself to the Mormonites, and been ordained an elder of those fanatics. Is the giving up of a rational being to the dominion of superstition, a legitimate cause for exultation? But Mr. Phelps once before in life made a mistake. He joined himself to the Masonic imposture; But he had the good sense to quit that well-organized band of ruffian[s] and cut-throats — and we doubt not, when reason shall have resumed her mind in his mind, he will also abandon the equally false, yet far more innocent, association with which he is now joined’.
http://www.olivercowdery.com/smithhome/Phelps/PhelpsSources1.htm