I just bought some concert tickets for October in a distant city for the wife & I, so I immediately started researching the bidding zones and hotels. I bid as soon as I had my information together. I got a bid accepted that was in the right range, and slightly less than half the hotel's website rate.

If I'd had getting a bid accepted at a reasonable price, I would have sat on it, bidding weekly using the same bidding strategy. If I noticed that the hotel websites started to increase for my dates, or started showing sellouts, I would have increased my bidding range.

Farthest out I've bid was 8 months out for a Hawaii trip, but our dates were pretty fixed. I was using award tickets, we both had to jump through hoops to schedule it with work, etc.

I've bid dozens of times the day before, or even the morning of a stay.

Lots of it comes from experience. I have about a half dozen cities where I'm very familiar with PL pricing (SAT, COS, DAL, PHX, BOS, HNL). I rarely pay more than I need to in those cities, and can, most of the time, predict the hotel. You might need plenty of lead time in HNL and during one or two times of the year in BOS. All the others can wait until close to the date unless there are events in town that fill up the hotels.

I guess I've just rambled for several paragraphs to say what everyone else said - it depends.