Change of date and How to avoid Peak out of time?

Things here in NJ are a bit slow in terms of racing events. Two promoters have already retired and I have had to change the date of my event twice. The first time I changed it while in the base phase, I think that in this phase they don’t involve making any changes. But today I have to change my date again for three weeks later from March 7 to 29.
While in the construction phase, how can this affect my training and performance? What can I do in this situation so as not to peak out of time? I want to prolong my form for at least two months.