Rain Dates: I Am Undecided

I need some advice... mostly because I’ve been sitting on this conundrum for the last few weeks and I have a lot of questions.

Here it is: 

Rain dates…

     Are they rude? 

          Are they appropriate for large functions?

               And what about small functions?

                    Are they a MUST for outdoor events?

                         See?

                              I told you I had a lot of questions….

I understand the point of a rain date:  to give another date to hold an outdoor party if the original date has unfavorable weather. 

However, can this be considered rude?  The idea that a guest will not only have to clear a few hours on one day for a party, but possibly a few hours on another day?  Would it be better to just have another place to hold a party if the weather turned ugly?  Or is it the duty of a guest to set aside ample time for a host or hostess’ party no matter what the time frame? 

Is a rain date appropriate for large and small functions?  I could understand a rain date for a large wedding to be held outside, but what about a small dinner party with only a few guests?  Do you put off plans for a small get together for a different weekend so you can use the awesome lanterns you bought on sale at Target (and I say that as Tar-jhay)?

I am undecided.  

I can’t find much as far as advice anywhere from Emily Post to Wikipedia. 

Personally, I think that the ‘rain date’ idea would only be used for larger events, such as a wedding, because so much time and effort has been put into the planning….  However lots of planning goes into dinner parties so why not have a rain date?!  (See I’m talking in circles and asking questions again.)

I’m sure I am not the only one with a question on this topic, has anyone been able to solve this dilemma?  Do you have any opinions?  I will certainly keep researching, but I want to know what ya’ll think!!