Autocreating related appointments for Outlook or Gmail

Autocreating related appointments for Outlook or Gmail

I work in a job which requires me to go out to sites to perform work, then
create reports based on the outcomes. The referrals come from a number of
different companies, and there are often differences in the SA's (Service
Agreements) for report turnaround time, and this varies again depending on
the type of work I have performed at a site.
In order to be most efficient, and to ensure I meet report turnaround
times, I am searching for an add-on which would allow me to create
appointment categories, then automatically create appointments / reminders
some days later so I have the date I need to complete the report by
already in my calendar.
Ideally it would work like this; I'd select an appointment type; 'Work
Visit A - Company X', then create the details of that appointment.
However, two appointments would be made, 1 for when I scheduled, and
another 3 days afterward. The subject line of this appointment wouldn't
matter, but it's just to have in the calendar.
Does this exist anywhere? My office uses outlook, but I will / am able to
use any calendar service out there.
Thanks for the time!