So i need help with a program i own a business that that need monthly service , im tired of having to look back in my books and remember is there a program that i can hit a button and pull up monthly accounts that need work

Exp joe i changed his ac filter 2/27/2019 needs filter changed 3/27/2019

Excel? Set up triggers to show you when a certain amount of time has passed.

So i can set this up and it will alert me to call or send my customer an email that there maintenance is do , and some can be month by month or bi monthly ?

yes
theres tons of programs that can do what your asking as well.
excel just better cause you can maintain books also

I mean you can use google docs/sheets with reminders if you don't have or want to pay for office.
There are a bunch of mobile apps out there as well, both office and google can be used on PC/Mobile so I'd start there.