After submitting your manuscript, waiting is the hardest thing for any writer. Patience is truly a virtue to be nurtured. Although writer's guidelines indicate response times, often editors do take longer. When editors are interested in a piece, they may hold the article for further consideration. Some editors may send a note advising that they are interested and holding the manuscript. Other editors, however, may hold a piece without notifying the author, leaving the writer frustrated.
Many writers are unacquainted with behind-the-scene activities at publishing companies. Writers remain blissfully ignorant of the mounds of manuscripts through which editors must plow searching for the perfect one. Writers often remain unaware of editors other responsibilities such as teaching, lecturing at conferences, critique services, and writing their own pieces.
I recall an instance early in my writing career when I wrote to an editor asking for an update. It was about a month past the indicated response time in the guidelines. The editor wrote back advising me of her many other duties and stressing patience. She pointed out that editors often do not have the time to respond to individual inquiries. If writers are anxious about their manuscripts, some editors may return them rather than deal with an inpatient author.
If you are a writer with little patience, then try simultaneous submissions or queries. Keep several pieces circulating and don't sit around waiting to hear from one editor before sending out a new piece.