I think that if you have very specific ideas about the ceremony/reception site and the date, you may need to book it in advance. Also, if it is on a holiday or is a destination wedding, give several months’ notice (save the date or invites) so your guests can prepare.

But no, I would advice against a very long engagement. Don’t become engaged lightly, but when you are, go ahead and get married. The longer it gets put off the bigger deal it becomes and it’s much more likely to cause more anxiety and cost a LOT more money.
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Most people say that a *typical* relatively formal mid-size wedding requires about 1 year of preparation time.

This was the guideline I used, although I would say that after booking the venue (it was a hotel so it took care of food, alcohol, etc.), I completed everything else in a total of less than 2 months, with a few last minute confirmations and details about 1 month before. Then you just sit back and wait. I felt that being very efficient and organized helped at lot. If you remain calm, prioritize, and cross things off your list, things will go smoothly.

I have seen many gorgeous weddings planned in less than 3 months (if you can get a venue, DJ, etc. it’s possible), and many simple weddings that took over 1 year.

Some people do not handle stress well, and such, they cannot ration their time properly. Others are undecided about what they want (some even up to a month before the wedding!). Aside from these issues, most brides who end up planning 2 years in advance either are just really excited and can’t wait, or they live in a large city and/or are having a very large complicated, lavish, and/or holiday weddings.

In most cases, once your venue is booked and you have ordered your dress, 6 months should be sufficient. Sometimes you will need to order your gown up to 8-12 months in advance. I had my gown custom made by a local designer, so that was one less thing to worry about. I had it made to fit (less alteration), and it was done in less than 1 month. It definitely helped.

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My best friend planned her DW in three months.

It all depends on what you want to do, the availability of your vendors/locations, the kind of guests you are having, etc.

For example, I'm planning my 2009 wedding but was able to lock in 2008 rates for planning earlier so its cheaper. My best friend planned hers within 3 months and had to choose very expensive photographers because all of the cheaper (and really the good ones) were already booked. She has also had to rush everything…her favors, her dress, her invites…so she had that extra added costs.
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