Either is acceptable. Publication more often than once a month is usually too time demanding and not really feasible. In fact, many would contend that monthly publication is too frequent. Whatever cycle a school sets for itself, it is important that the deadlines be met. If publications are constantly running late, the school's credibility and reader loyalty will suffer.
Newsletters tend to build a following, and readers want their news regularly and on time.
Certain articles should be slated for certain issues every year. Of course, specific sports are featured in specific issues. Certain events, such as Christmas programs, music contests, academic events, reminders of upcoming dates, etc., are routinely featured. For example, in the fall issue of our newsletter, we introduce new faculty members, describe new high school courses, and graph achievement test results from the previous spring. Some articles should appear in every issue of the newsletter.