There are two questions:
1) what do your by-laws say about publicizing changes
2) what should you do to make sure no one complains that they didn't know

Certainly you should put it on the agenda for Feb and March -- best if you aren't changing the by-laws at the April meeting to say that elections are that month, if people didn't plan to attend April but were planning to run in May.

It would be nice if you could send home a paper notice of one of these agendas, with the election change highlighted.

We have in our by-laws election of officers are in May and we are needing to chance it to April. We have to give 30 days notice. How should the notice be written to publicize the proposed chance?