"The Massachusetts Colony Records, under the date of the twenty-third of August, of the same year, give the following: 'It was ordered, that there should be a Court of Assistants held at the Governor's house on the 7th day of September next, being Tuesday, to begin at 8 of the clock.' [note: spelling modernized] This meeting was held at Charlestown (where it is to be inferred that the Governor dwelt) on the appointed day, and then the ever memorable order was passed which gave to the peninsula the name it now bears. The exact record which chronicles the naming of the three important towns is: 'It is ordered, that the Trimountaine shalbe called Boston; Mattapan, and Dorchester; & the towne vpon Charles Ryuer, Waterton.'"
From A Topographical and Historical Description of Boston (1891) by Nathaniel Shurtleff.
In honor of the naming and chartering of Boston on 7 September 1630, a variety of organizations have joined forces to create a program of events celebrating Boston's founding. The link below, to the website for the Partnership of Historic Bostons, will provide you with the full schedule of events. I am particularly looking forward to the panel discussion on "Boston's Cultural Continuities and Changes Since 1630", which will be held Thursday, 7 September starting at 6 P.M. at the Rabb Lecture Hall at the Boston Public Library, Copley Square and to the Charter Day Sabbath Gathering at First Church in Boston at the corner of Berkeley and Marlborough Streets on Sunday, 10 September at 11 A.M.