fiancee visa timeline question

Hello,
This will probably be one of a number of questions I ask. I will soon be applying for the family of a settled person visa to be with my fiancée. Just have a very basic timeline question for now.
Hopefully all will go well with the application and I can soon be with my fiancée in the UK. If that is the case, how long is the visa good for. By that I mean, is it good for say 30 days from my listed attended travel date.
For example, let's say I put in December 20th as my attended travel date, and my visa application gets approved, does that mean I can leave for the UK anytime from December 20th till around January 10th. And can not leave until at least the 20th of December.
Second timeline question, lets say I applied and got approved for the visa on October 20th, will I still be okay leaving on December 20th if I listed that as my attended date. I think I was getting mixed up with the marriage visitor which had something about it being a 3 month process from start to end. Thank you.

You can apply up to 3 months ahead of your intended travel date, so if you're looking to travel 20 Dec, the earliest you could apply would be 20 Sept.

The visa is supposed to be valid from the date you list on your application as your intended travel date (historically, this hasn't always been the case, but with the new entry requirements, the ECO should be abiding by the applicant's stated travel date). 

The visa will be valid for 30 days to enter the UK once valid.  So, if the visa is valid from 20 Dec, you would have 30 days to enter the UK (and you could enter the UK anytime after 20 Dec, but before the 30 days are up).  Once in the UK, you would need to collect your BRP from the designated post office within 10 days. 

If you cannot enter the UK within the 30 day timeline, you would need to pay a fee and apply for an extension to allow you more time to move to the UK.

Thanks. Just to be clear. In the example of December 20th, is the September 20th date the date from the time I finish the application online or from the date they receive the application.
If I finished the application online on say the 15th but by the time I have my Biometrics done and sent in the application, they don't get it till say the 25th of September. Does the 3 month clock start on the 15th, meaning if I put December 20th as my attended date, I have to wait till the 20th to finish filling out the application online. Or will I need to have my attended date be at least the 25th or after when they actually receive the application.
Just trying to organize everything and want to let my fiancée know when she needs to have everything on her end sent to me, along with filling out the application myself. Thanks. 

As the fiancé visa is valid for 6 months, it is not subject to the new 'must enter within 30 days' requirement.  While they *should* honor your intended travel date, they don't always.  You need to be sure you will have time to register, marry, and apply for your next visa before the 6 month expiry date (can be tight in some areas).

The application date is the date you submit your application online.

Keep in mind you will need medical insurance and/or have to pay out of pocket for any NHS treatment before your next visa is issued.

Right now the plan is to move out there around the 2nd or 3rd week of December. Plan on getting married around the last week of March or first week of April. Does that give me enough time to apply for the second visa. That would make the 6 month period around the middle of June.
Thanks.

Should be fine.

Depending on if you pay for priority processing or not, I'd recommend applying early November.  Processing traditionally slows down mid-late November with lots of people applying hoping to move in time for Christmas.

Probably getting ahead of myself, but haven't really read much on applying for the second visa yet. Is that the FLR(M). If I filed in April, should I be able to get approved by June.
As far as applying in November instead of September, Does it matter when I apply as long as the attended date is still in December. Or do you recommend November as they might not honor my listed attended travel date and give me a much earlier travel date. Or is it just a case of the process taking longer if I apply in September. Thanks.

Should add that we do want to be together before Christmas. Probably should have made that clear. Thanks.

Yes, the next visa will be FLR(M).

Yeah, they aren't good about honouring intended travel dates.  I'd apply early November and use priority.  That way if it's issued on, say Novembr 10th, you'd still be okay with your six month window.  If you apply in September, they could make it valid in Serptember, thus screwing up your timeline.

They are starting to honor travel dates with the new requirement to enter within 30 days on other visa types but there haven't been enough fiancé visas issued in that time for us to know if they are using the requested travel date or not (they used to ignore it most of the time).

As long as you apply for FLR(M) before your visa expires, you are good.  You don't have to have the application approved before your expiration date.

For those people who have been recently approved for a Fiance visa under the new rules, has the intended travel date been honored. If not, what start date was listed on your visa. Thank you.

As the fiancé visa is valid for 6 months, it is not subject to the new 'must enter within 30 days' requirement.  While they *should* honor your intended travel date, they don't always.  You need to be sure you will have time to register, marry, and apply for your next visa before the 6 month expiry date (can be tight in some areas).

The application date is the date you submit your application online.

Keep in mind you will need medical insurance and/or have to pay out of pocket for any NHS treatment before your next visa is issued.

Is this for certain? Me and my fiance have a travel date of Sept. 27th and we still haven't gotten a decision yet so we have been extremely stressed thinking we were going to get the visa with a 30-day window to enter the UK.

Is this for certain? Me and my fiance have a travel date of Sept. 27th and we still haven't gotten a decision yet so we have been extremely stressed thinking we were going to get the visa with a 30-day window to enter the UK.

Definitely.

Once again, thanks for the help here. Have a couple other basic type questions before I really start getting everything ready so I can start applying for a Visa.

With the photo, can I just go to any pharmacy or post office that does passport photos and use passport photos as my visa photo. It seems there are slight differences between the two, but might be reading it wrong.

https://www.gov.uk/photos-for-passports

http://travel.state.gov/content/passports/en/passports/photos/photos.html

Also, for the return envelope, what size envelope would people recommend using.

Finally,
I have most of my original boarding passes from my trips visiting my fiancée and her visits here over the past few years. Should I send all the original boarding passes, or make copies on sheets of paper. Say 5 or so boarding passes on each sheet of paper or as I mentioned, should I just send in all the original boarding passes. 

Just some more basic type of questions. Thanks. 

You are fine to send in US standard passport photos versus the UK sized ones.

Use a return envelope that holds what you send.      I'd just shove the packaging for whichever company you choose to ship with (UPS or DHL).  Actually, I probably wouldn't even send packaging and expect the UKVI to use the appropriate envelope when returning.      But most people on here tend to include a return envelope.

How many boarding passes are you talking?  I would send the originals but it sounds like you might have a LOT of those.   

Had photo taken at post office and the passport photos they took of me, from the crown of my head to my chin measures around 25 mm and on UK Visa site, says it should be at least 29 to 34 mm. Should I be worried. Thanks.