The ACM Executive Committee has approved a policy whereby conferences and symposia require the approval of the ACM Conferences Board. This policy does not apply to regular local meetings or professional development seminars. People begin to stir after a long winter and are susceptible to new ideas. In the summer many people are away on vacation. Fall is good, except that some people are in school or launching other activities.
Winter offers unpredictable weather.
PDSs can be held during the day, on weekends, or in the evening. Evenings draw well, particularly where there is a large population base within an hour's drive of the chosen location. If the speaker is from out of town and is well known, one or two full days should work well. With a professional-looking publicity brochure, most companies would grant time off for good quality training. For evening seminars, a good plan used successfully is for meetings to be held on a series of successive Tuesdays, or Thursdays.