I get questions from clients and non-clients alike all the time, wanting to know what "good times for subbing" are, or suggesting that there is a time when "publishing grinds to a halt." Once again it came up on the last Open Thread: "The end of the year is typically a busy time for all of us, but, in general, is there a better time of year to query agents?"
Since I am on my way to a holiday, this seemed like an apt time to revisit the question.
The fact is, yes, of course, lots of people go on vacation in August, and the week of Thanksgiving, and the time between Hanukkah and January 4 or so. This is true in publishing as well as pretty much every other profession. I'm not quite sure why this is surprising to anyone.
However, when you are just querying agents, it doesn't matter when you do it. You are (usually) submitting unsolicited material, aka "slush", which most agents read in whatever spare time they can muster, in the order in which it is received. So what the hell, who cares when you query an agent? When your material is ready, send it out and get in line. If you wait until a good time, you'll be waiting till the crack of doom.
The only exception to this is the rare agent who takes a query holiday where they are closed to submissions entirely - if that is the case, though, it should be clearly posted on their website.
The other side of the coin: When I am subbing material to editors, I am usually pitching it to them in person (or via phone or email) first, and so generally avoid the week of Christmas/New Years, the last two weeks of August, and any time when there is madness like BEA or Bologna going on. This is partly because I don't want my material to get lost in the shuffle... and partly because I am too busy during those times!
But if I avoided all the federal holidays, all the Jewish holidays, all the Christian holidays, all the book fairs and conferences and scbwi events and and and... dude, I'd have like two non-consecutive viable weeks per year in which to submit. The fact is, publishing is a very slow business. Very. Very. Slow. As far as publishers go, it takes many people to make an offer, and to make a real book, and at least one of those people is ALWAYS on vacation or at a conference.
That said, I have gotten offers from publishers in the doldrums of August, and the week before Christmas, and at night, and on weekends, too. And I have offered representation to people during all those times. I've offered representation to people while I was vacationing in Hawaii. I've rejected people from airplanes (and I am sure I will do it again today!)
Do prepare, of course, but don't overthink it. When you are ready, press "send."