When to submits apps with schools that have rolling admissions

Im preparing to apply this cycle and I have finalized my list of schools. The schools with the earliest deadlines are on august 1st. However i believe half of the schools on my list are also rolling. I wish I could apply as soon as CASPA opens however I am still looking for an MD to write me a LOR (planning on asking one soon). Im giving myself a July 15th deadline to submit everything (and im giving my LOR's a deadline of mid june to finish their letters) but im wondering if that might be too late? Should I instead aim for July 1st? Mid june?

Another complication is that im going on a international trip late may-mid june. I dont want to waste my chances all because i submitted late.