The standard base-build-speciality progression takes 28 weeks. But if you enter your target event into the calendar as an A event, then Plan Builder will use whatever time is available to have you ready for your target even (whether this is more or less than 28 weeks).
Yesterday. And if you can’t manage that, the day before yesterday.
The longer out the better of you want to build base up. If you wanted to simply maintain your fitness and not follow a plan religiously then you can just hit it out of the park by just doing specialty or 2nd phase of build plus specialty. Most people peak in the 9 to 12 week range with intensity training. After that your body will want a rest!
I used to fart around just keeping fitness and riding for fun then hit the specialty gravity plan leading into Enduro season. Seemed to always work well. Once in season it was more mixing a few recovery weeks with the last couple of build weeks and a specialty week between races. Worked well enough at the time and rode mostly to how the body felt. And found this easier to maintain over a four month / five race season.
Just delete the current plan or unridden rides. Then start the plan builder.
You can back date the start date if you just want to jump in at build.
When it asks what your experience is with training, if you select towards the left hand of the options it will lean more to base and less specialty. If you select towards the right, then there will be less base and more build and specialty. It’s really asking “have you done some base, are you fit already?”
My A race is in June next year and I started a plan over a year ago but thats mainly down to this wee c thing. I had already postponed the race due to medical reasons from June 2019 to June 2020, pre my use of TR. The wee c thing then postponed it to June 2021. I then joined TR (July 2020) and set up a plan to that date, it was subsequently postponed to September 2021 and now June 2022. Each time it was just a case of editing the date and letting plan builder re-calculate.