Other than Zapier, Slack reminders are a huge help to us. We have reminders set up for all sorts of things, both recurring and adhoc. If you use Slack and don't use reminders, look into how it works, they are fantastic.
We also use https://sweep.cards/ which is from Amy Hoy, who many of you may know of. It's basically for things that don't go in a calendar but which are recurring in some fashion, such as doing payroll each month, weekly reviews, or even minor daily tasks you need to remember to do. It has group workflow for this stuff as well if there are multiple people who need to do a single piece of a recurring task.
We also use https://sweep.cards/ which is from Amy Hoy, who many of you may know of. It's basically for things that don't go in a calendar but which are recurring in some fashion, such as doing payroll each month, weekly reviews, or even minor daily tasks you need to remember to do. It has group workflow for this stuff as well if there are multiple people who need to do a single piece of a recurring task.