Best Month To Start/End Lease

[Frances Evans]

I have a great family who have been renting an upper-end North Scottsdale 4Br/3BA home for the past four years.  Their lease ends March 1st but they have asked if they can go month-to-month for a few months because they want to explore the buying.  

I am happy to accommodate them for a short time - as long as it does not put me into a bad month to find a new tenant. I definitely do not want to go past August 1st.  I am looking for feedback from anyone who knows this market well as to what the best month would be to have a lease start/end.  Would appreciate it if anyone can point me to  some data that shows the rental market month by month.